• 한국광학회:학술대회논문집
• /
• 한국광학회 1999년도 제16회 광학 및 양자전자 학술발표회Proceedings of 16th Optics and Quantum Electronics Conference, 1999
• /
• pp.14-15
• /
• 1999

• 천문학회보
• /
• 제31권2호
• /
• pp.66-66
• /
• 2006

• 천문학회지
• /
• 제29권2호
• /
• pp.93-105
• /
• 1996

We have solved the radiative transfer problem using a Sobolev approximation with an escape probability method in case of the supersonic expansion of a stellar envelope to an ambient medium. The radiation from the expanding envelope turns out to produce a P-Cygni type profile. In order to investigate the morphology of the theoretical P-Cygni type profile, we have treated $V_\infty,\;V_{sto},\;\beta$ (parameters for the velocity field), it and E(parameter for collisional effect) as model parameters. We have investigated that the velocity field and the mass loss rate affect the shapes of the P-Cygni type profiles most effectively. The secondarily important factors are $V_\infty,\;V_{sto}$. The collisional effect tends to make the total flux increased but not so much in magnitude. We have infered some physical parameters of 68 Cyg, HD24912, and $\xi$ persei such as $V_\infty,\;M$ from the model calculation, which shows a good agreenment with the observational results.

• Mass Spectrometry Letters
• /
• 제10권1호
• /
• pp.27-31
• /
• 2019

In this article, the properties of ${CO_2}^+(CO_2)_n$ clusters in a Paul ion trap have been investigated using mass-selective instability mode which conducted by chosen precursor ions, mainly $Ar^+$ and ${CO_2}^+$ produced by a mixture of Ar and $CO_2$. Exposure of ${CO_2}^+$ ions to $CO_2$ molecules, lead to the formation of ${CO_2}^+(CO_2)_n$ clusters. Here, Ar gas react as a buffer gas and lead to form ${CO_2}^+(CO_2)_n$ cluster by collisional effect.

• 천문학회지
• /
• 제41권3호
• /
• pp.49-58
• /
• 2008

Resonance doublets including O VI 1032, 1038, NV 1239, 1243 and C IV 1548, 1551 constitute prominent emission lines in symbiotic stars and planetary nebulae. Spectroscopic studies of symbiotic stars and planetary nebulae from UV space telescopes show various line ratios of these doublets deviating from the theoretical ratio of 2:1. Using a Monte Carlo technique, we investigate the collisional de-excitation effect in these emission nebulae. We consider an emission nebula around the hot component of a symbiotic star characterized by the collisional de-excitation probability $p_{coll}\;{\sim}\;10^{-3}\;-\;10^{-4}$ per each resonance scattering, and the line center optical depths for major resonance doublets in the range ${\tau}_0\;{\sim}\;10^2\;-\;10^5$. We find that various line ratios are obtained when the product $p_{coll}{\tau}_0$ is of order unity. Our Monte Carlo calculations show that the flux ratio can be approximately fitted by a linear function of ${\log}{\tau}_0$ when ${\tau}_0p_{coll}\;{\sim}\;1$. It is briefly discussed that this corresponds to the range relevant to the emission nebulae of symbiotic stars.

• 천문학회지
• /
• 제29권spc1호
• /
• pp.263-264
• /
• 1996

We have solved the radiative transfer problem using a Sobolev approximation with an escape probability method in case of the supersonic expansion of a stellar envelope to an ambient medium. The radiation from the expanding envelope turns out to produce a P-Cygni type profile. In order to investigate the morphology of the theoretical P-Cygni type profile, we have treated $V{\infty},\;V_{sto},\;{\beta}$ (parameter for the velocity field), M and $\epsilon$ (parameter for collisional effect) as model parametrs. We have found that the velocity field and the mass loss rate affect the shapes of the P-Cygni type profiles most effectively. The secondarily important factors are $V{\infty},\;V_{sto}$. The collisional effect tends to make the total flux increase but not so .much in magnitude. We have infered some physical parameters of 68 Cyg, HD24912, and $\xi$ persei such as V$\infty$, M from the model calculation, which shows a good agreement with the observational results.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1989년도 하계종합학술대회 논문집
• /
• pp.447-450
• /
• 1989

Single particle orbit in plasma is obtained by drift Hamiltonian formulation in magnetic coordinate. The collisional effect is implied by Monte Carlo Method and the velocity space diffusion, energy transfer to the back ground plasma and the variation of energy distribution of test particles are investigated from many particles analysis.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제40회 동계학술대회 초록집
• /
• pp.245-246
• /
• 2011

Emission lines ratios were used for diagnostics of and excited level densities in low-temperature plasmas. In this work, an optical emission spectroscopy (OES) was used to determine the electron temperature and metastable level densities in low-pressure inductively coupled plasma. The emission spectroscopy method was based on a simple collisional-radiative model. The selected lines of the Ar(4p to 4s) were influenced by the radiation trapping at relatively high pressures where the plasma become optically thick. To quantify this effect, a pressure dependence factor ${\alpha}$(P) was derived by using corrections for the measured intensities. It was found that the lower metastable level densities were obtained when ${\alpha}$(P) increased with the increasing discharge pressure. The effect of non-Maxwellian electron energy distribution functions (EEDFs) on the metastables was also presented and discussed.

• Bulletin of the Korean Chemical Society
• /
• 제17권1호
• /
• pp.56-60
• /
• 1996

The pressure saturation effect on the phosphorescence decay rates of the $^3B_1$ State of $SO_2$ has been reinvestigated by the laser induced phosphorescence method in pure $SO_2$. We have attempted to fit the pressure dependence of the phosphorescence decay rates using the radiationless transition model by introducing different coupling constants for each vibrational level ofthe 3B1 state. The experimental decay rates can be fitted well, when the coupling constants for the (0,0,0), (0,1,0) and (0,2,0) levels of the $^3B_1$ state are $7.2\;{\times}\;10^{-4}$, $2.2\;{\times}\;10^{-3}$ and $5.9\;{\times}\;10^{-3}\;cm^{-1}$, respectively.

• KSBB Journal
• /
• 제22권1호
• /
• pp.48-52
• /
• 2007

본 연구에서는 sonificator를 장착하여 세포막을 파쇄하고 현장에서 형광을 이용하여 조작이 간편하고 단시간에 DNA와 단백질을 동시에 측정할 수 있는 자동화된 형광기를 개발하기 위하여 단백질을 측정하는데 최적의 파쇄조건을 확립하고자 하였다. 용액 중에 녹아 있는 공기 중의 oxygen은 collisional quenching을 일으키는데 sonification이나 가열처리를 시키면 oxygen이 제거되어 quenching 효과가 크게 감소되어 높은 형광값을 나타내었다. 0.7 X 이상의 형광시약 농도에서는 반응시작 후 1분 이내에 측정해야 하며, 0.3 X 이하의 형광시약 농도에서는 반응시작 후 2$\sim$3분 사이에 반응을 시킨 후 측정하는 것이 바람직한 것으로 나타났다. $100{\mu}g/m{\ell}$ 이상의 BSA 농도에서는 형광시약이 포화되었으며, 시료를 sonification시키면 단백질이 변성되어 눈에 보일 정도로 불투명해져서 시료 용액의 불투명도로 인해 형광 값이 감소되는 경향을 나타내었으며, $1{\mu}g/m{\ell}$ 이하의 BSA 시료에서는 sonification을 시키지 않은 시료보다 sonification을 시켰을 때 $0.125{\mu}g/m{\ell}$의 BSA를 훨씬 더 구분이 잘 되어 낮은 단백질 농도에서는 sonification시키는 것이 훨씬 유리한 것으로 나타났다.