• Transactions of the Korean Society of Automotive Engineers
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• v.9 no.6
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• pp.112-118
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• 2001

In this study the leakage current measurement method based on a porous ceramic is applied to check the conductive substance caused by the ionized particles. By using engine and chassis dynamometer and an experiment vehicle, in which the hydrocarbon sensor (HC sensor) was exposed to the exhaust gas to create the electrical signal, the HC sensor in the exhaust line checked the conductive ions in emission gas. Generally the output electrical signal of HC sensor is followed with amount of hydrocarbon in the experiments in cold start and operation. By combining the electrical signal, a measure of conductivity of exhaust gas with hydrocarbon can be provided by OBD (On Board Diagnosis) II and EMS (Engine Management System).

• Laser Solutions
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• v.5 no.3
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• pp.15-20
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• 2002

The principal obstacle to selection of a laser processing method in production is its relatively high equipment cost and the natural unwillingness of production supervision to try something new until it is thoroughly proven. The major objective of this work is focused on the combined features of gas tungsten arc and a low-power cold laser beam. In this work, the laser beam from a 7 watts carbon monoxide laser was combined with electrical discharges from a short-pulsed capacitive discharge GTA welding power supply. When the low power CO laser beam passes through a special composition shielding gas, the CO molecules in the gas absorbs the radiation, and ionizes through a process blown as non-equilibrium, vibration-vibration pumping. The resulting laser-induced plasma(LIP) was positioned between various configurations of electrodes. The high-voltage impulse applied to the electrodes forced rapid electrical breakdown between the electrodes. Electrical discharges between tungsten electrodes and aluminum sheet specimens followed the ionized path provided by LIP. The result was well-focused melted spots.

• Journal of The Korean Astronomical Society
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• v.40 no.4
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• pp.127-129
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• 2007

It is well known that water vapor maser emission at 22.2 GHz is associated with the earliest stages of both low- and high-mass star formation and it can be considered a reliable diagnostic of their evolutionary state. Bright Rimmed Clouds (BRCs) are clouds that have been compressed by an external ionization-shock front which focuses the neutral gas into compact globules. The boundary layer between the neutral gas and the gas ionized by the incident photons is often called "bright rim" but the clumps are sometimes classified also as speck globules or cometary globules depending on their appearance. Small globules with bright rims have been considered to be potential sites of star formation and have been studied in several individual regions. We present results from high resolution VLA observations searching for new candidates of recent star formation in bright-rimmed clouds/globules associated with IRAS point sources.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.69.2-69.2
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• 2010

The far-ultraviolet (FUV) H2 and C IV emission images and spectra of Orion Eridanus Superbubble (OES) is hereby presented. The OES seems to consists of multiple phase through the detection of highly-ionized gas and pervasive neutral hydrogen. The former is traced by hot gas while the latter is traced by cold medium. A spectral image made with H2 fluorescent emission shows that the spatial distribution of hydrogen molecule is well correlated with the dust map. The model spectra was taken from a photodissociation region (PDR) radiation code which find a best suitable parameter such as hydrogen density, gas temperature and incident uv intensity of the radiation field. C IV emission is caused by intermediate temperature ISM about 10^4.5 K~10^6 K. Therefore we could get more clear evidence to reveal the structure of OES. Feature of spectra for the each sub region is also presented and discussed. The data were obtained with the Far-Ultraviolet Imaging Spectrograph (FIMS) and the whole data handling were followed by previous FIMS analysis.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.2
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• pp.71.1-71.1
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• 2010

The far-ultraviolet (FUV) C IV and H2 emission spectra of Orion-Eridanus Superbubble (OES) is hereby presented. The OES seems to consist of multiple phase through the detection of highly-ionized gas and pervasive neutral hydrogen. The former is traced by hot gas while the latter is traced by cold medium. A spectral image made with H2 fluorescent emission shows that the spatial distribution of hydrogen molecule is well correlated with the dust map. The model spectra was taken from a photodissociation region (PDR) radiation code which finds a best suitable parameter such as hydrogen density and intensity of the radiation field. C IV emission is caused by intermediate temperature ISM about 10^5 K. Therefore we could get more clear evidence to reveal the morphology of OES. In this process, the hydrogen density and gas temperature were also estimated. The data were obtained with the Far-Ultraviolet Imaging Spectrograph (FIMS) and the whole data handling were followed by previous FIMS analysis.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.554-557
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• 2003

This paper describes the information for quantitative simulation of weakly ionized plasma. We should grasp the meaning of the plasma state condition to utilize engineering application and to understand materials of plasma state. In this paper, electron swarm parameter in He+Xe and Ar+He mixture gas calculated for range E/N values $0.01{\sim}500$ [Td] at the temperature is 300 [K] and pressure is 1 [Torr], using a set of electron collision cross sections determined by the authors, and using a method of Backward Prolongation by two term approximation Boltzmann equation method, for basic study on the gas discharge panel.

• Nuclear Engineering and Technology
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• v.53 no.5
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• pp.1464-1478
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• 2021

Selective Production of Exotic Species is an innovative plant for advanced nuclear physic studies. A radioactive beam, generated by using an UCx target-ion source system, is ionized, selected and accelerated for experimental objects. Very high vacuum conditions and appropriate safety systems to storage exhaust gases are required to avoid radiological risk for operators and people. In this paper, Failure Mode, Effects, and Criticality Analysis of a preliminary design of high activity gas recovery system is performed by using a modified Fuzzy Risk Priority Number to rank the most critical components in terms of failures and human errors. Comparisons between fuzzy approach and classic application allow to show that Fuzzy Risk Priority Number is able to enhance the focus of risk assessments and to improve the safety of complex and innovative systems such as those under consideration.

• Journal of Environmental Science International
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• v.30 no.5
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• pp.399-406
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• 2021

The dissolution of ionized gas in dielectric barrier plasma, similar to the principle of ozone generation, is a major performance-affecting factor. In this study, the plasma gas dissolving performance of a gas mixing-circulation plasma process was evaluated using an experimental design methodology. The plasma reaction is a function of four parameters [electric current (X₁), gas flow rate (X₂), liquid flow rate (X₃) and reaction time (X₄)] modeled by the Box-Behnken design. RNO (N, N-Dimethyl-4-nitrosoaniline), an indictor of OH radical formation, was evaluated using a quadratic response surface model. The model prediction equation derived for RNO degradation was shown as a second-order polynomial. By pooling the terms with poor explanatory power as error terms and performing ANOVA, results showed high significance, with an adjusted R² value of 0.9386; this indicate that the model adequately satisfies the polynomial fit. For the RNO degradation, the measured value and the predicted values by the model equation agreed relatively well. The optimum current, gas flow rate, liquid flow rate and reaction time were obtained for the highest desirability for RNO degradation at 0.21 A, 2.65 L/min, 0.75 L/min and 6.5 min, respectively.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.266-268
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• 1998

The linear MHD(magnetohydro-dynamic) machine obtains the linear motion by replacing the solid conducting secondary of LIM with the ionized gas, plasma or the liquid metal. The electromagnetic pump which is a kind of MHD machine is divided into induction pump and conduction pump. This paper shows the classification and development trends of MHD machines and the characteristics of double sided flat linear induction pump (DFLIP).

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.11
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• pp.1252-1257
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• 2004

This paper describes the information for quantitative simulation of weakly ionized plasma. In previous paper, we calculated the electron transport coefficients by using two-term approximation of Boltzmann equation. But there is difference between the result of the two-term approximation of the Boltzmann equation and experiments in pure CF$_4$ molecular gas and in CF$_4$+Ar gas mixture. Therefore, In this paper, we calculated the electron drift velocity (W) in pure CF$_4$ molecular gas and CF$_4$+Ar gas mixture (1 %, 5 %, 10 %) for range of E/N values from 0.17～300 Td at the temperature was 300 K and pressure was 1 Torr by multi-term approximation of the Boltzmann equation by Robson and Ness. The results of two-term and multi-term approximation of the Boltzmann equation have been compared with each other for a range of E/N.