• Title/Summary/Keyword: Corona

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Effect of Corona Discharge Treatment on the Dyeability of Low-density Polyethylene Film

  • Park, Soo-Jin
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.35-36
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    • 2003
  • The purpose of this work is to investigate the surface modification of LDPE film via corona discharge treatment and subsequent graft polymerization, and their effect on the resulting dyeability is studied in terms of the surface functional groups, surface energetics, and acid-base interaction between the modified LDPE and the dyes used.

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신설 345KV 초고압 송전선 주변지역 전파장해 예측 - 라디오 수신장해

  • 양배덕
    • 전기의세계
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    • v.24 no.5
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    • pp.16-20
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    • 1975
  • 초고압 송전선에 의한 전파장해는 주로 Corona 잡음에 의한 라디오 수신장해와 전파산란에 의한 TV수신장해 및 기타 무선 통신에 영향을 주는 잡음장해가 있다. 본고에서는 먼저 초고압 송전선에서의 Corona 잡음 특성을 논하고 신설 345KV 송전선 주변에서의 라디오 장해 범위를 예측해 보고자 한다.

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A SCANNING CCD DETECTOR FOR SOLAR ECLIPSE OBSERVATIONS

  • YERSHOV V. N.
    • Journal of The Korean Astronomical Society
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    • v.29 no.spc1
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    • pp.385-386
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    • 1996
  • A wide-field CCD detector for solar eclipse observations is discussed. The CCD is supposed to be of a moderate size, and the image of the corona is obtained by scanning the field of view. Results of the 1995 solar eclipse observation are shown which have been made with a prototype of the scanning CCD detector.

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Post-corona and semiconductor industry: The risk of separation of the semiconductor value chain triggered by Corona 19 and the response strategy of the Korean semiconductor industry (포스트 코로나와 반도체 산업 : 코로나19로 촉발된 반도체 밸류체인 분리 위험과 한국 반도체 산업의 대응전략)

  • Kim, Kiseop;Han, SeungHun
    • Journal of Technology Innovation
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    • v.28 no.4
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    • pp.127-150
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    • 2020
  • The World Health Organization (WHO) declared the third pandemic in history after the Hong Kong flu and swine flu. The outbreak of Corona 19 dramatically reduced exchanges between countries, while rapid contagion created a time gap in economic fluctuations by country. In January 2020, the trade dispute between the US and China entered into a consensus phase, but the economic decoupling phenomenon caused by Corona 19 made it difficult for China to balance trade with the US and made it difficult to comply with the terms of the trade dispute agreement between the US and China. President Trump attributed the responsibility for the spread of Corona 19 to China, and pointed out that the cause of the economic downturn was the infringement of Chinese trade secrets and illegal copies, and protectionism arose. As a result, China protested fiercely, and the conflict with the United States deepened. The US has declared trade sanctions on Huawei and SMIC, which are key companies in China's semiconductor industry, and is predicting the risk of a disconnection of the semiconductor value chain between the US and China. The separation of the value chain of the semiconductor industry has the potential to have a big impact on the semiconductor industry, a structure that is highly specialized and monopolized by certain countries and companies in the value chain. This paper aims to deal with the risk of disconnection in the semiconductor value chain between the US and China reignited by Corona 19, the impact and change of the global semiconductor industry value chain, and the response strategies of Korean semiconductor companies.

Non-Thermal Plasma Technique for Removing $SO_2$ and $NO_x$ from Combustion Flue Gas (연소가스내 탈황탈질처리를 위한 저온 플라즈마 기술)

  • Song, Yeong-Hun;Sin, Wan-Ho;Kim, Seok-Jun;Jang, Gil-Hong
    • 한국연소학회:학술대회논문집
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    • 1997.06a
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    • pp.69-76
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    • 1997
  • Industrial-scale pulse corona process to remove $SO_2$ and $NO_x$ simultaneously from combustion flue gas has been studied. The pilot plant built in the present study treats 2,000 $Nm^3$/hr of flue gas from a boiler. The geometry of the pulse corona reactor is similar to that of an electrostatic precipitator commonly used in industry, A thyratron switch and magnetic pulse compressors, which can generate up to 130 kV of peak pulse voltage and up to 30 kW of average pulse power, have been used to produce pulsed corona. The removal efficiencies of $S0_2$ and $NO_x$ with the present process are maximum of 95 % and 85 %, respectively. Electrical power consumption to produce the pulsed corona, which has been one of the major difficulties to apply this process to industry, has been evaluated in the present study. The results showed that the power consumption can be reduced significantly by simultaneous addition of hydrocarbon injection and heterogeneous phase reactions to the process.

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Study on the Reduction of Energy Consumption in the Pulsed Corona Discharge Process for NOx Removal (질소산화물 제거를 위한 펄스코로나 방전공정의 에너지 소모 저감에 관한 연구)

  • 정재우;손병학;조무현;목영선;남궁원
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.4
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    • pp.475-483
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    • 1999
  • A lab-scale test was carried out to study the reduction of electrical energy consumption in the pulsed corona discharge process for nitrogen oxides removal. The experiment was mainly focused on 1) the activation of pollution removal reactions by chemical additives and 2) the optimization of electrical circuit for the efficient energy transfer from the power supply to the corona reactor. Hydrocarbon chemical additives used in the experiment are thought to be responsible for the enhancement of the NO conversion through the chain reactions of free radicals such as, R, RCO, and RO. Electrical energy consumption per converted NO molecule has a minimum value of 17 eV when pentanol is injected. When ethylene and propylene are injected, 30 eV and 22 eV of electrical energy consumption is required for the conversion of NO molecule respectively. The ratio of the pulse forming capacitance$(C_e)$ to the reactor capacitance$(C_R)$ plays an important role in the energy transfer efficiency to the reactor. Maximum energy transfer efficiency of approximately 72% could be obtained by using the pulse forming capacitance which is 3.4 times larger than the reactor capacitance, and also the maximum NO conversion efficiency was observed with the same condition.

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A NON-SPHERICAL MODEL FOR THE HOT OXYGEN CORONA OF MARS

  • KIM YONG HA;SON SUJEONG;YI YU;KIM JHOON
    • Journal of The Korean Astronomical Society
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    • v.34 no.1
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    • pp.25-29
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    • 2001
  • We have constructed a non-spherical model for the hot oxygen corona of Mars by including the effects of planetary rotation and diurnal variation of the Martian ionosphere. Exospheric oxygen densities are calculated by integrating ensemble of ballistic and escaping oxygen atoms from the exobase over the entire planet. The hot oxygen atoms are produced by dissociative recombination of $O^+_2$, the major ion in the Martian ionosphere. The densities of hot oxygen atoms at the exobase are estimated from electron densities which have been measured to vary with solar zenith angle. Our model shows that the density difference of hot oxygen atoms between noon and terminator is about two orders of magnitude near the exobase, but reduces abruptly around altitudes of 2000 km due to lateral transport. The diurnal variation of hot oxygen densities remains significant up to the altitude of 10000 km. The diurnal variation of the hot oxygen corona should thus be considered when the upcoming Nozomi measurements are analyzed. The non-spherical model of the hot oxy-gen corona may contribute to building sophisticate solar wind interaction models and thus result in more accurate escaping rate of oxygens from Mars.

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