• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.339-339
• /
• 2011

진공 플라즈마와 달리 개방된 공간에서 방전되는 대기압 플라즈마는 진공상태에서 수행되는 에칭, 증착 등의 복잡한 플라즈마 공정을 경제적이고 신속하게 수행할 수 있어, 최근 들어 연구가 활발히 진행 중이다. 이와 관련하여 He, Ar, $N_2$, $O_2$, Air 등의 여러 종류의 기체를 50 kHz 고전압에서 방전하여 대기 중에서 저온 플라즈마 공정이 가능한 아크젯 타입의 플라즈마 소스를 개발하였다. 개발된 플라즈마 소스에서는 입력전압, 기체유량, 노즐의 구조와 크기 등의 여러 운전변수에 따라 플라즈마의 방전특성이 변화되었다. 특히 본 연구에서는 아크젯의 플라즈마 발생부의 물질성분(SUS, Aluminum, Cupper)에 따른 플라즈마의 기체온도 및 전자여기 온도의 변화를 광방출분광법(OES)를 이용한 Synthetic spectrum method와 Boltzmann plot method을 통해 살펴보았다. 전압-전류 특성곡선, 시간분해 이미지 촬영법, 기체온도 측정법 등을 이용하여 발생된 플라즈마의 물리적인 특성을 분석하였다. 특히 물질의 성분에 따라 발생되는 플라즈마의 기체 및 전자여기 온도가 이차 전자 방출계수 및 물질의 전도도와의 상관관계가 있는지 연구가 진행 중이다.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.4
• /
• pp.777-782
• /
• 2009

In this paper, the effect of the secondary electron emission coefficient of Xe ion on glow discharge was examined by ID numerical simulation. The simulation was performed for two distinct structures, short and long gaps. The features of the glow discharges in the both structures, firing and sustain voltages, luminance, and efficiency, were analyzed at various secondary electron emission coefficient of Xe ion.

• Proceedings of the KAIS Fall Conference
• /
• 2002.05a
• /
• pp.257-259
• /
• 2002

원적외선은 파장이 매우 긴 빛으로 우리 생활에 가장 유익한 빛이다. 이는 인체에 전혀 해가 없이 생체 활동을 촉진하는 광선으로 숙성, 온열, 자정, 건조, 연수 등 다양한 작용을 하는 불가사의한 빛으로 알려져 있다. 현재 원적외선을 활용한 분야는 건설, 주택, 가전제품, 의류, 화장품, 농업에 이르기까지 다양하고, 그 과는 이미 많은 부분에서 입증되고 있다. 본 연구는 기능이 향상된 원적외선을 방사하는 기능성 포장재에서 딸기의 이차학적 변화를 관찰하고 나아가 신선도를 향상시키는 식품 포장재를 개발하는 것에 그 목적을 두었다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.419-422
• /
• 1995

In this paper, we propose two methods for AE source location on the material with unknown AE wave velocity. By this method, we can apply this method to arbitrary material of which properties are not known exactly. Also, in this paper, the mechanism of error generation in both methods are discussed and performances are compared by using computer simulation and experiments which uses a lead break as the AE source on the aluminum plate.

• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 2003.11a
• /
• pp.151-152
• /
• 2003

대기중에는 토양입자나 해양입자와 같이 직접적으로 방출되는 입자상 물질 이외에 자연적으로 생성되거나 인간의 활동에 의하여 배출되는 유황, 질소산화물 및 유기물의 가스상 물질이 대기 화학 반응에 의하여 입자상 물질로 변환된 이차입자가 혼재되어 있다. 이러한 입자상물질은 $K^{＋}$, $Na^{＋}$, $Mg^{2+}$, NH$_4$$^{+}$, $Ca^{2+}$ 등의 양이온과 Cl$^{-}$, NO$_3$$^{-}$, SO$_4$$^{2-}$ 등의 음이온 성분으로 구성되어 있다. (중략)

• Proceedings of the Korean Vacuum Society Conference
• /
• 2006.02a
• /
• pp.111-111
• /
• 2006

• Proceedings of the Korean Vacuum Society Conference
• /
• 2005.08a
• /
• pp.146-146
• /
• 2005

• Journal of Korean Society of Forest Science
• /
• v.111 no.4
• /
• pp.490-501
• /
• 2022

In this study, the isoprene and terpene emissions from 32 major urban tree species were investigated. We conducted sampling using a dynamic enclosure system between June and July 2021. Seedlings aged < three years were enclosed in a chamber consisting of a 400 L transparent Tedlar bag. The air flow from the outlet of the chamber was sampled using Tenax-filled sorbent tubes under standard conditions (temperature: 30°C; PAR: 1,000 μmol/m²/sec). A thermal desorption gas chromatography/mass spectrometry system was used to analyze the following 38 biogenic volatile organic compounds: isoprene, monoterpenes, sesquiterpenes, oxygenated monoterpenes, and oxygenated sesquiterpenes. Isoprene emitters included Quercus mongolica, Salix koreensis, Robinia pseudoacacia, and Salix chaenomeloides. Monoterpene emitters included Pinus strobus, Cedrela sinensis, and Cercis chinensis. The monoterpene emission profiles were dominated by á-pinene, myrcene, camphene, and limonene. The predominant oxygenated monoterpene and oxygenated sesquiterpene were eucalyptol and caryophyllene oxide, respectively. For all species, the contributions of sesquiterpenes and oxygenated sesquiterpenes were relatively low.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.44 no.12
• /
• pp.12-17
• /
• 2007

The effects of the evaporation rate of MgO films using an electron beam on the MgO properties and the discharge characteristics of a plasma display panel(PDP) were investigated and analyzed. Mgo films were deposited with the various MgO evaporation rates. The MgO properties such as the crystal orientation, the surface roughness, and the film structure, were inspected using XRD(X-ray diffractometry), AFM(atomic force microscopy). From the experiments and Paschen law, the maximum value of the secondary, electron emission coefficient $(\gamma)$ was obtained at the evaporation rate of $5\AA/sec$. The minimum firing voltage and the maximum luminous efficiency were obtained at an evaporation rate of $5\AA/sec$. In the MgO film deposited at $5\AA/sec$, the (200) orientation and $F^+$ center were most intensive. The XRD results and cathode-luminescence(CL) spectra show the $\gamma$ values are correlated with $F/F^+$ centers of the molecular structure of MgO films.

• Journal of the Korean Vacuum Society
• /
• v.12 no.1
• /
• pp.16-19
• /
• 2003

Ni thin films on the p-InP (In) substrates were grown at room temperature by using the ion beam-assisted deposition. In order to determine the work function of the Ni thin films, the $\gamma$values were measured as functions of the acceleration voltages by using Ne, Ar, $N_2$. and Xe ion sources. The dependences of the values on various gases and on the acceleration voltages of the focused ion beam were obtained to determine the work function of the Ni thin films. The value of the work function of the Ni thin films grown on the p-InP (100) substrate was 5.8 eV ~ 5.85 eV. These results provide important information on the electronic properties of Ni thin films grown on p-InP (100) substrates at room temperature.