• Journal of the Korean Institute of Telematics and Electronics
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• v.21 no.5
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• pp.41-45
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• 1984

The production of high-quality epitaxial layers almost always involves an etching step of silicon substrates with HCl gas prior to epitaxy, In this work, an investigation has been made on the etch rate and the etch-pit formation as a function of HCl gas concentration and etch temperature at atmospheric pressure (1 atm.) and reduced pressure (0.1 atom.). As a result, it is found that the etch rate is proportional to the square of the HCI gas concentration (XHC12) and the apparent ativation energy is between 0 and 111 Kcal/mole for both ammospheric and reduced pressure operation. From these results, it is expected that the HCI etching of silicon in reduced pressure operation proceeds, as in atmospheric operation, via the reaction ; Si + 2HCl ↔ SiCl2 + H2.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.9 no.1
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• pp.14-19
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• 1999

Using a single precursor of hexamethyldisilane $(Si_{2}(CH_{3})_{6})$, $\beta$-SiC film was successfully deposited on a Si substrate at $1100^{\circ}C$ by a chemical vapor deposition method. Selectivity of SiC deposition on a Si substrate partially covered with a masking material was investigated by introducing HCl gas into hexamethyldisilane/$H_{2}$ gas system during the deposition. The schedule of the precursor and HCl gas flows was modified so that the selectivity of SiC deposition between a Si substrate and a mask material should be improved. It was confirmed that the selectivity of SiC deposition was improved by introducing HCl gas. Also, the pulse gas flow technique was effective to enhance the selectivity.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.09a
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• pp.91-95
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• 1998

Selectivity of SiC deposition on a Si substrate partially covered with a masking material was investigated by introducing HCl gas into hexamethyldisilane/H2 gas system during the deposition. the schedule of the precursor and HCl gas flows was modified so that the selectivity of SiC deposition between a Si substrate and a mask material should be improved. It was confirmed that the selectivity of SiC deposition was improved by introducing HCl gas. Also, the pulse gas flow technique was effective to enhance the selectivity.

• Bulletin of the Korean Chemical Society
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• v.29 no.4
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• pp.782-784
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• 2008

Ag/Ni bimetallic cluster loading on porous carbon fibers was accomplished in order to enhance the HCl removal efficiency of the carbons. The surface properties of the Ag/Ni/carbons were determined by XRD and SEM. N2/77 K adsorption isotherms were investigated using BET and Boers t-plot methods. The HCl removal efficiency was confirmed by a gas chromatography technique, and it was found that that efficiency was predominantly improved in the presence of Ag/Ni clusters compared with the efficiencies of the as-received and single-metal-plated carbons. This indicates that synergetic reactions exist between Ag/Ni and HCl gas, resulting in advanced HCl removal capacity of porous carbons.

• Fire Science and Engineering
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• v.29 no.4
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• pp.57-60
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• 2015

The removal efficiencies by elastic fire gas mask of toxic gases CO, HCl, HCN, and $SO_2$ produced by a fire have a key role in saving lives. The elastic fire gas mask comprises a visible window, elastic hood, gas purification canister, and air vent. It does not have hair or neck thongs, which makes it easy to use and put on quickly. This research examined the removal efficiency of toxic gases by such a mask. The removal efficiencies for CO with a background concentration of 2505.0 ppm were 99.99 and 99.98% after 3.5 and 8.5 min, respectively. The residual CO concentration was drastically increased after 8.5 min. The removal efficiencies for HCl, HCN, and $SO_2$ with background concentrations of 1003.0, 399.0, and 100.3 ppm, respectively, were 100% after 20 min.

• YAKHAK HOEJI
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• v.19 no.4
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• pp.240-245
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• 1975

The quantitative analysis of ethambutol.2HCl as well as commercial ehambutol preparations was undertaken by gas-liquid chromatography by finding optimum conditions, such as the use of internal standard, stability of an ethambutol-2HCl-caffeine standard solution, and the effect of column temperature, N, O-bis-(trimethylsily) acetamide [B.S.A.] concentrations and other substances present in the preparations. Under the chromatiographic conditions, an ethambutol-2HCl. caffeine standard, 9 min, 30sec. The relative molar response of ethambutol.2HCl and caffeine studied was 2.08. Ethambutol.2HCl could be quantitated up to 1$\times$10$^{-8}$ moles. the possible decomposition of B.S.A. due to the moisture when tested and the incoplete reaction for silylation could be minimized.

• Clean Technology
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• v.19 no.2
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• pp.165-172
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• 2013

In this study, the hydrogen chloride removal using K-based dry sorbents ($K_2CO_3/Al_2O_3$, KEPRI, Korea) was studied with varying the pressure in a fixed bed reactor (15 cm tall bed with 0.5 cm I.d.). Working temperature was $400^{\circ}C$ and feed gas concentration was 750 ppm (HCl vol%, $N_2$ balance). The chloride sorption capacity of sorbent increases with increasing pressure (1, 5, 10, 15 and 20 bar). Also, after forming KCl crystal by reaction with $K_2CO_3$ and HCl, owing to the strong bonding energy, sorbent regeneration was practically impossible. Its optical, physical and chemical characterizations were evaluated by SEM, EDAX, BET, TGA and XRD. At $400^{\circ}C$ and 20 bar condition, working condition for the dehalogenation process after gasification, K-based dry sorbent showed high HCl sorption capacity and HCl/$N_2$ separation performances comparing with Ca-based and Mg-based dry sorbents.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1995.11a
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• pp.97-101
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• 1995

GaN films were prepared on Si(111) substrates by hydride vapor phase epitaxy (HVPE) on HCl-NH$_3$-N$_2$gas system. Effects of HCl gas flow rate on the film investigate under deposition conditions of flow time of 10min, 20min, 30min. The deposition rate increased with increasing HCl gas flow rate in the range of 10cc/min to 40cc/min and deposition time. Strung (00.2) oriented GaN film was obtained at a lower HCl flow rate and improved of the surface morphology.

• Journal of the Korea Organic Resources Recycling Association
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• v.18 no.1
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• pp.66-72
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• 2010

This study was done to analyze the condition of combustion exhaust gas that is produced according to incinerator operating condition in A area Kyonggido. The boiler exhaust gas temperature, the oxygen concentration of boiler, the outgassing temperature of Semi Drying Sorber(SDS), the temperature of catalytic reactor, the concentration of NOx, SOx, CO, Hcl and Dust were investigated by change the temperature of incinerator. The concentration of SOx, CO, HCL and DUST were below 5 ppm as increase the temperature of incinerator however the concentration of NOx was increased from 40 ppm to 70 ppm as increase the temperature of incinerator. The boiler exhaust gas temperature and the temperature of catalytic reactor were not changed however the oxygen concentration of boiler was decreased gradually as increase the temperature of incinerator.

• Carbon letters
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• v.5 no.3
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• pp.103-107
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• 2004

The atmospheric pressure plasma treatments ($Ar/O_2$ and $Ar/N_2$) of activated carbon fibers (ACFs) were carried out to introduce hydrophilic functional groups on carbon surfaces in order to enhance the hydrogen chloride gas (HCl) adsorption. Surface properties of the ACFs were determined by XPS and SEM. $N_2$/77 K adsorption isotherms were investigated by BET and D-R (Dubinin-Radushkevich) plot methods. The HCl removal efficiency was confirmed by HCl detecting tubes (range:1~40 or 40~1000 ppm). As experimental results, it was found that all plasma-treated ACFs showed the decrease in the pore volume, but the HCl removal efficiency showed higher level than that of the untreated ACFs. This result indicated that the plasma treatments led to the conformation of hydrophilic functional groups on the carbon surfaces, resulting in the increase of the interaction between the ACFs and HCl gas.