• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.10
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• pp.909-913
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• 2002

The luminance and discharge characteristics of ac PDP may be significantly affected by a small amount of impurity gas in working gas. These impurity gases such as O$_2$, O, C and H$_2$ can be mixed in the manufacturing and /or discharge process. In this paper a small amount of impurity gas in acPDP are introduced quantitatively and the relationship between the amount of impurity gas and the luminance/discharge characteristics are investigated. The luminous efficiency decreased seriously with increase in the partial pressure of impurity gases, especially in H$_2$, O$_2$ and CO$_2$. Under the condition of the impurity gas ratio of 2${\times}$10$\^$-3/ for Ar, N2, H$_2$, CO$_2$ and O$_2$, the luminous efficiency decreased about 8%, 8%, 32%, 36% and 50%, respectively.

• Journal of Information Display
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• v.2 no.4
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• pp.29-33
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• 2001

The luminance and discharge characteristics of an AC PDP may be significantly affected by a small amount of impurity gas in working gas. Impurity gases such as $O_2$, O , C and $H_2$ can be mixed in the manufacturing and lor discharge processes. In this paper, a small amount of impurity gas in AC PDP are introduced intertimally and the relationship between the amount of impurity gas and the luminance/discharge characteristics are investigated. The luminous efficiency decreased seriously with the increase in the partial pressure of impurity gases, especially in $H_2$, $O_2$ and $CO_2$, Under the condition of the impurity gas ratio of 2x $10^{-3}$ for Ar, $N_2$, $H_2$, $CO_2$ and $O_2$, the luminous efficiency decreased to about 8%, 8%, 32%, 36% and 50%, respectively.

• Journal of the Korean Vacuum Society
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• v.8 no.4A
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• pp.482-489
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• 1999

AC PDP(P1asma Display Pane1)s use the mixture of inert gases to generate a discharge inside the display pixels. Impurities such as CO, $CO_2$ and OH inside discharge region may deteriorate the characteristics of PDP operation during long life time of PDP. Electro-negative gas such as CO can cause the sustain pulse amplitude to rise by attaching electrons which will play an important role in the earlier stage of the discharge. MgO film is used to protect the dielectric layer in AC PDP, and is in contact with the free space of display pixel where it is filled with the inert gas mixture. So, MgO film can be a main source of impurities. In this experiment, we observed the change of impurity generation of various MgO films which were deposited by different methods, by using QMS. (quadropole mass spectrometer) The main impurites were $H_2$, CO and $CO_2$. And with the comparison of the TPD (temperature programmed desorption) result, it can be understood that impurity gases are generated by sputtering of MgO surface not by outgassing. Deposition method had effects on the characteristics of the impurity generation. The MgO film manufactured by e-beam evaporation generated more amount of impurity gases than the MgO films manufactured by sputtering or ion-plating. And also heat treatment of MgO film after deposition decreased the magnitude of impurity gas generation.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2117-2119
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• 1999

In this paper, the electric fields inside GIS with metal impurity is analysed by the use of 3 dimensional Surface Charge Method. We find the metal impurity makes electric field distribution inside GIS non-uniform and causes breakdown of $SF_6$ gas in GIS.

• Bulletin of the Korean Chemical Society
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• v.25 no.2
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• pp.233-236
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• 2004

Total impurity analysis of a primary standard solution is one of the essential procedures to determine an accurate concentration of the standard solution by the gravimetry. Bi impurity is determined in Pb standard solutions by inductively coupled plasma mass spectrometry (ICP-MS). The direct nebulization of the Pb standard solution produces a significant amount of the Pb matrix-induced molecular ions which give rise to a serious spectral interference to the Bi determination. In order to avoid the spectral interference from the interferent $^{208}PbH^+$, the hydride generation method is employed for the matrix separation. The Bi hydride vapor is generated by reaction of the sample solution with 1% sodium borohydride solution. The vapor is then directed by argon carrier gas into the ICP after separation from the mixture solution in a liquid-gas separator made of a polytetrafluoroethylene membrane tube. The presence of 1000 ${\mu}$g/mL Pb matrix caused reduction of the bismuthine generation efficiency by about 40%. The standard addition method is used to overcome the chemical interference from the Pb matrix. Optimum conditions are investigated for the hydride-generation ICPMS. The detection limit of this method is 0.5 pg/mL for the sample solutions containing 1000 ${\mu}$g/mL Pb matrix.

• YAKHAK HOEJI
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• v.37 no.1
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• pp.76-83
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• 1993

The changes in discharge current, emission and/or oscillation frequency of the electric oscillation of a glow discharge are the potential sensitive measure of the concentration of an impurity in the argon plasma supporting gas. A single jet enhanced glow discharge has been interfaced with the gas chromatograph via 1/8" O.D. tube with a heating pad to study the changes in discharge current. To investigate the optimum operating conditions of the glow discharge system as detector for gas chromatography, pressure, gas flow rate, discharge current, distance between the anode and the cathode have been studied.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.588-595
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• 2020

This study examined the catalytic property of Ni-catalyst used in the gas purifying process to manufacture inert gases of N2 and Ar with high-purity over 9N for semiconductor industrial applications. Two types of Ni-catalysts with a cylindrical shape (C1) and churros shape structure (C2) were compared for the assessment. Optical microscopy and FESEM were used to analyze the shape and microstructure of the Ni-catalyst. EDS, XRD, and micro-Raman characterization were performed to examine the composition and properties. BET and Pulse Titration analyses were conducted to check the surface area and catalytic property of the Ni-catalyst. From the composition analysis results, C1 contained a relatively large amount of graphite as an impurity, and C2 contained higher Ni contents than C1. From specific surface area analysis, the specific surface area of C2 was approximately 1.69 times larger than that of C1. From catalytic property analysis, outstanding performance in O₂ and CO impurity removal was observed at room temperature. Therefore, C2, having low-impurity and large specific surface area, is a suitable catalyst for the high-purity inert gas process in the semiconductor industry because of its outstanding performance in O₂ and CO impurity removal at room temperature.

• YAKHAK HOEJI
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• v.42 no.6
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• pp.627-633
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• 1998

Impurity profiling analysis of methamphetamine seized in Korea was investigated for the evidential and intelligent purpose. Samples were extracted with ethylacetate which contai ns internal standard of dioctylsebacate under basic condition and extracts were analyzed by GC-FID. Ephedrine, chloroephedrine & 1,2-dimethyl-3-phenylaziridine were identified impurities in illicit methamphetamine by GC-MS. These impurities revealed that most of abused methamphetamine in Korea were synthesized from ephedrine as a starting material. For the classification of samples. firstly, 24 impurity peaks were selected after inspection of every peak in 50 samples as the specific markers of impurities. Secondly, corresponding peak retention time and area ratio to the internal standard were calculated and database was created with values of 24 peaks by in-house program. Finally, cluster analysis was attempted with the resultant profiles using the STAR plot, which was based on the Euclidian distance for evaluating similarity among samples. A total of 76 samples were divided into 8 different groups within 90% statistical similarity and inter-batch samples showed similar impurity patterns by this procedure. In conclusion, the analysis of impurities is a suitable index for estimation the common or different origin of methamphetamine sample.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.6
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• pp.670-676
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• 2016

Hydrogen town in Republic of Korea was established in 2013. Hydrogen as a byproduct produced by various processes of factories is used in hydrogen town facilities. As cell performance is affected by contaminations in fuel gas, various standards about impurities of fuel have been determined by many countries. This study shows performance degradation of single cell with impurities concentrations. Traces of carbon monoxide (CO) and hydrogen sulfide ($H_2S$)can cause considerable cell performance losses. For comparing the performances by poisoning of CO, acceleration test, I-V curve, constant current are performed. Both the CO and $H_2S$ poisoning rate are a function of their concentration. With the higher concentrations the higher poisoning rates are observed. And, it was confirmed that, oxidation behavior and side reaction generation are not affected. Under the lower $H_2S$ concentration condition, the poisoning rate is much higher than that of CO because of its different adsorption intensity. It can be possible that the result of this study can be used for enacting regulation as a baseline data.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.320-323
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• 2007

The vacuum sealing method is adopted to minimize the residual impurity gas by enhancing a base vacuum level, and the resultant changes in the reset, address, and sustain discharge characteristics, such as a firing voltage, IR emission, and ICCD image, were examined in comparison with the conventional sealing method in the 42-in. AC-PDP. In the PDP cells fabricated by the vacuum sealing method, the ICCD observation illustrates that the discharge is initiated and extinguished very fast and its IR emission intensity is high.