• Title/Summary/Keyword: HCl gas

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Extension of the Site Binding Model for Ion Sensing Mechanism of ISFET and Its Application to the Hydrogen Ion Sensing $Si_3N_4$ Membrane (ISFET 이온감지기구의 Site Binding 모형 확장과 그 $Si_3N_4$ 수소이온 감지막에의 적용)

  • Seo, Hwa-Il;Kwon, Dae-Hyuk;Lee, Jong-Hyun;Sohn, Byung-Ki
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.25 no.11
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    • pp.1358-1366
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    • 1988
  • The dual dielectric films have been grown on single-crystalline silicon substrates with the thickness ranging from 125A to 180A at various gas and temperature conditions by using rapid thermal process that included independent nitridation step. The film characteristics and their dependence on the contents of the hydrochloric gas and the processing time have been studied. By the addition of the hydrochloric gas, the initial oxide thickness was significantly changed, but after sequential nitridation processes the thickness of the films was nevertheless a little bit varied within 10A. All the samples of the dual dielectric films show the increased breakdown voltages in proportion to the additive contents of the hydrochloric gas and also show the higher breakdown strengths than the thermal oxide and nitrided oxide films grown by the conventional furnance process or the rapid thermal nitridation process that was composed of the dependent nitridation cycles.

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Efficient Management of the pH of the Wet Scrubber Washing Water for Risk Mitigation (리스크 완화를 위한 Wet Scrubber 세정수 pH의 효율적 관리)

  • Joo, Dong-Yeon;Seoe, Jae Min;Kim, Myung-Chul;Baek, Jong-Bae
    • Journal of the Korean Society of Safety
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    • v.35 no.6
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    • pp.85-92
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    • 2020
  • Wet Scrubber reacts the incoming pollutant gas with cleaning water (water + absorbent) to absorb pollutants and release the clean air to the atmosphere. Wet scrubbers and packed tower scrubbers using this principle are widely used in businesses that emit acid gases. In particular, in the etching process using hydrochloric acid (HCl), alkaline washing water (NaOH) having a pH of about 8 to 11 is used to absorb a large amount of acid gas. However, These salts are attached to the injection nozzle (nozzle), filling material (packing), and the demister (Demister), causing air pollution, human damage, and inoperability due to clogging and acid gas discharge. Therefore, In this study, an improvement plan was proposed to manage the washing water with pH 3~4 acidic washing water. The test method takes samples from the Wet Scrubber flue measurement laboratory twice a month for 1 year. Hydrogen chloride (HCl) concentration (ppm) was measured, and nozzle clogging and scale conditions were measured, compared, and analyzed through a differential pressure gauge and a pressure gauge. As a result of the check, it was visually confirmed that the scale was reduced to 50% or less in the spray nozzle, filler, and demister. In addition, the emission limit of hydrogen chloride in accordance with the Enforcement Regulation of the Air Quality Conservation Act [Annex 8] met 3 ppm or less. Therefore, even if the washing water is operated in an acidic pH range of 3 to 4, it is expected to reduce air pollution and human damage due to clogging of internal parts, and it is expected to reduce maintenance costs such as regular cleaning or replacement of parts.

CARS Spectra of HCI, N₂, and C₂H₂ in the Gas Phase

  • 백선종;김중희;박주연;이성열;김홍래
    • Bulletin of the Korean Chemical Society
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    • v.16 no.9
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    • pp.810-813
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    • 1995
  • Coherent anti-Stokes Raman scattering (CARS) spectra of HCl, N2, and the ν1 fundamental of C2H2 have been measured in the gas phase. The measured spectra show rotational structures which originate from the Q-branch transitions. The spectra have successfully been simulated with proper selection rules, line positions, and relative intensities from room temperature Boltzmann population distributions. The vibration-rotation interaction constant α of HCl in the ground electronic state has been measured from the rotationally resolved CARS spectra which is α=0.3076 cm-1. Possibilities of optical pumping and of measuring state specific energy distributions of molecules are discussed.

Selective Si Epitaxy for Device Isolation (소자분리를 위한 선택적 실리콘 에피택시)

  • Yang, Jeon Wook;Cho, Kyoung Ik;Park, Sin Chong
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.23 no.6
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    • pp.801-806
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    • 1986
  • The effect of SiH2Cl2 -HCl gas on the growth rate of epitaxial layer is studied. The temperature, pressure and gas mixing ratio of SiH2Cl2 and HCl are varied to study the growth rate dependence and selective Si epitaxy. The P-n junction diode is fabricated on the epitaxial layer and electrical characteristics are examined. Also, using selective Si epitaxy, a possibility of thin dielectric isolation process, that gives an independent isolation width on the mask dimension, is examined.

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High Efficiency Hybrid Ion Exchange Chemical Filter for Removal of Acidic Harmful Gases (산성유해가스 제거를 위한 고효율 음이온교환 복합 폼 화학필터의 제조)

  • Jung, Youn Seo;Kim, In Sik;Hyeon, Seung Mi;Hwang, Taek Sung
    • Applied Chemistry for Engineering
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    • v.28 no.5
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    • pp.539-546
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    • 2017
  • In this study, an outstanding anion exchange chemical filter was prepared for acidic gas removal. Commercial anion exchange resin was attached to polyurethane (PU) foam by using different types of pressure sensitive adhesive (PSA). The water and chemical resistance and also adhesive elongation were investigated. Also, the behavior of HCl and HF adsorption was evaluated as functions of the initial concentration and flow rate. ATE-701, AT-4000C and HCA-1000 showed 900, 1,500% and 2,400% of the elongation, respectively. It was confirmed that the desorption ratio of HCA-1000 was less than 6% and had excellent durability in water and chemical resistance tests. The adsorption occurred faster as the concentration and flow rate of HCl and HF increased. But 100% adsorption equilibrium occurred after 110 minutes, regardless of the concentration and flow rate. In addition, SEM morphology showed that the adhesive was uniformly dispersed, while the porous structure of the ion exchange resin was maintained, and the chemical filter exhibited excellent durability for the adsorption/desorption process.

The Influence of $C_2HCl_3$ on the $CH_4/Air$ Counterflow Nonpremixed Flames (메탄/공기 대향류 비예혼합화염에서 $C_2HCl_3$의 영향)

  • Lee, Ki-Yong
    • Journal of the Korean Society of Combustion
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    • v.3 no.2
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    • pp.41-50
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    • 1998
  • Numerical simulations of nonpremixed $CH_4/C_2HCl_3$(Trichloroethylene, TCE)/Air flames are conducted at atmospheric pressure in order to understand the effect of hydrocabon bound chlorine on methane/air flames. A chemical kinetic mechanism is employed, the adopted scheme involving 48 gas-phase species and 445 elementray reaction steps containing 223 backward reactions. The calculated temperature, velocity, and critical strain rate are compared with the experiments for the flame (16.1% TCE by Vol.) estabilished at a strain rate of $175s^{-1}$. Whereas there is overall good agreement between predictions and the measurements, it appears that the critical strain rate is higher than measured, and some areas of further refinement in the kinetic mechanism are required.

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Understanding and Improvement of an Experiment Measuring Chemical Reaction Rates by Monitoring Volume Change of a Gas:On the Reaction between HCl(aq) and Mg(s) (기체 부피변화를 이용한 화학반응속도 측정 실험의 이해 및 개선 연구: HCl 수용액과 고체 Mg의 반응에 대하여)

  • Jeong, Dae-Hong;Bang, Jeong-A;Yun, Hui-Suk;Choe, Won-Ho
    • Journal of the Korean Chemical Society
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    • v.50 no.5
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    • pp.404-414
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    • 2006
  • this study we analyzed and improved an experiment measuring chemical reaction rates introduced in the high school science textbooks through an understanding of the phenomena observed in carrying out the experiment. For this purpose, the contents of textbooks related to the experiment were analyzed, and the problems observed in carrying out the experiment were addressed through experimental analysis. When the experiment was carried out by the method of aquatic transposition presented in textbooks, the observed volume change of H2 gas was delayed and chemical reaction rate was increased in the early stage of reaction period. To resolve these problems, an improved method for measuring the reaction rates was suggested. In the improved experiment the reaction rate was measured to be constant on time, which was interpreted in terms of the concentration of H+ and the surface area of magnesium.

Pulse Stretching Effect in XeCl Excimer Laser (XeCl 엑시머 레이저에서의 Pulse Stretching 효과)

  • Chu, Hong;Kim, Dong-Hwan;Lee, Soo-Man;John, Young-Min;Choi, Sang-Sam;Park, Dae-Yoon
    • Korean Journal of Optics and Photonics
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    • v.4 no.4
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    • pp.447-451
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    • 1993
  • Long pulse XeCl excimer laser with 150 ns (FWHM) pulse duration is developed using a simple capacitor-charge transfer circuit. We measured the laser pulse width varying the gas mixture ratio and capacitance ratio, which dominantly affect the pulse width. In this way we can easily stretch the pulse width from short pulse to long pulse. The pulse width was stretched by 120 ns as the partial pressure of HC1 and Xe gas was reduced under constant gas mixture ratio ([Xe]/[HCl]= 15), and by varying the capacitance ratio (Cm/Cp) under fixed pressure, the pulse width was stretched by 60 ns.

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Development of MA Packaging Materials for Freshness Extension of Fruits and Vegetables(2) (과실 채소류의 MA포장용 소재의 효과제고에 관한 연구(2))

  • Park, Hyung-Woo;Park, Jong-Dae;Kim, Byung-Sam;Kim, Hoon;Yang, Han-Chul
    • KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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    • v.4 no.1
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    • pp.17-21
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    • 1997
  • Zeolite powder used by molecular sieve, adsorbants and catalist. 1N HCl teated zeolite powders for freshness extension of fruits and vegetables showed that specific surface area was $300.29m^2/g$ largest then that of the others, and ethylene gas adsorbability was 29.07 cc/g. And then 0.5N NaCl Henting after 1N HCl treated zeolite powder showed that specific surface area and ethylene gas adsorbability was $329.43m^2/g$ and 35.64 cc/g largest then those of the others. Specific surface area of processed zeolite powder treated by high intensity magnetic seperator(HIMS) showed $369.67m^2.g$, ethylene gas adsorbability was 39.87cc/g. In this study, it could be employ 0.5N NaCl treat and HIMS methods as MA packaging materials for freshess extension of fruits and vegetables.

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Low-Temperature Selective Epitaxial Growth of SiGe using a Cyclic Process of Deposition-and-Etching (증착과 식각의 연속 공정을 이용한 저온 선택적 실리콘-게르마늄 에피 성장)

  • 김상훈;이승윤;박찬우;심규환;강진영
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.8
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    • pp.657-662
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    • 2003
  • This paper presents a new fabrication method of selective SiGe epitaxial growth at 650 $^{\circ}C$ on (100) silicon wafer with oxide patterns by reduced pressure chemical vapor deposition. The new method is characterized by a cyclic process, which is composed of two parts: initially, selective SiGe epitaxy layer is grown on exposed bare silicon during a short incubation time by SiH$_4$/GeH$_4$/HCl/H$_2$system and followed etching step is achieved to remove the SiGe nuclei on oxide by HCl/H$_2$system without source gas flow. As a result, we noted that the addition of HCl serves not only to reduce the growth rate on bare Si, but also to suppress the nucleation on SiO$_2$. In addition, we confirmed that the incubation period is regenerated after etching step, so it is possible to grow thick SiGe epitaxial layer sustaining the selectivity. The effect of the addition of HCl and dopants incorporation was investigated.