• Title/Summary/Keyword: Ar-$H_2$

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Corrosion Behavior of Inconel X-750 for Carbon Anode Oxide Reduction Application

  • Jeon, Min Ku;Kim, Sung-Wook;Lee, Sang-Kwon;Choi, Eun-Young
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.18 no.3
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    • pp.355-362
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    • 2020
  • The corrosion behavior of the Inconel X-750 alloy was investigated for its potential application under a Cl2-O2 mixed gas flow in an Ar atmosphere. The corrosion rate was found to be negligible at temperatures up to 400℃ under a flow rate of 30 mL·min-1 Cl2 + 170 mL·min-1 Ar, whereas an exponential increase was observed in the corrosion rate at temperatures greater than 500℃. The suppression of the corrosion reaction due to the presence of O2 was verified experimentally at flow rates of 30 mL·min-1 Cl2 (4.96 g·m-2·h-1), 20 mL·min-1 Cl2 + 10 mL·min-1 O2 (2.02 g·m-2 ·h-1), and 10 mL·min-1 Cl2 + 20 mL·min-1 O2 (1.34 g·m-2·h-1) under a constant Ar flow rate of 170 mL·min-1 at 600℃ for 8 h. The surface morphology analysis results revealed that porous surfaces with tunnel-type holes were produced under the Cl2-O2 mixed-gas condition. Furthermore, the effects of the Cl2 flow rate on the corrosion rate were investigated, indicating that its impact was negligible within the range of 5-30 mL·min-1 Cl2 at 600℃.

The effect of Astragali Radix and Armeniacae Semen on the apoptosis of immunocytes and nitric oxide production from peritoneal macrophages (황기와 행인(杏仁)이 면역세포(免疫細胞)의 Apoptosis 및 Nitric Oxide에 미치는 효과(效果))

  • Jeong Hyun-Woo;Moon Han-Ju
    • Herbal Formula Science
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    • v.6 no.1
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    • pp.175-186
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    • 1998
  • The purpose of this research was to investigate effects of Astragali Radix(AR) and Armeniacae Semen(AS) on T-lymphocytes and peritoneal macrophages in mice. The proliferation of thymocytes and splenocytes were teated using macroplate-reader. The apoptosis and sub-population of T-lymphocytes were tested using a flow cytometer. Nitric oxide production was tested using a Griess reagents. The result were obtained as follow; 1. AR increased the proliferation of thymocytes and splenocytes. 2. AS decreased the proliferation of thymocytes and splenocytes. 3. AR and AS decreased No production fron peritoneal macrophages 4. AR and AS were accelerate T-lymphocytes apoptosis. 5. AR and AS increased $T_C$ cells population, but decreased $T_H$ cells population of T-lymphocyte.

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Effect of Heat Treatment Environment on the Densification of Cold Sprayed Ti Coating Layer (저온 분사 공정으로 제조된 티타늄 코팅층의 치밀화에 미치는 열처리 분위기의 영향)

  • Yu, Ji-Sang;Kim, Hyung-Jun;Oh, Ik-Hyun;Lee, Kee-Ahn
    • Journal of Powder Materials
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    • v.19 no.2
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    • pp.110-116
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    • 2012
  • This study investigated the effects of annealing environment for the densification and purification properties of pure titanium coating layer manufactured by cold spraying. The annealing was conducted at $600^{\circ}C$/1 h and three kinds of environments of vacuum, Ar gas, and $5%H_2+Ar$ mixture gas were controlled. Cold sprayed Ti coating layer (as sprayed) represented 6.7% of porosity and 228 HV of hardness, showing elongated particle shapes (severe plastic deformation) perpendicular to injection direction. Regardless of gas environments, all thermally heat treated coating layers consisted of pure ${\alpha}$-Ti and minimal oxide. Vacuum environment during heat treatment represented superior densification properties (3.8% porosity, 156.7 HV) to those of Ar gas (5.3%, 144.5 HV) and $5%H_2+Ar$ mixture gas (5.5%, 153.1 HV). From the results of phase analysis (XRD, EPMA, SEM, EDS), it was found that the vacuum environment during heat treatment could be effective for reducing oxide contents (purification) in the Ti coating layer. The characteristic of microstructural evolution with heat treatment was found to be different at three different gas environments. The controlling method for improving densification and purification in the cold sprayed Ti coating material was also discussed.

The effect of $Ar\;+\;H_2$ Plasma on the Low Temperature ITO Film Synthesized on Polymer (폴리머 기판상에 합성된 저온 ITO 박막에 미치는 $Ar\;+\;H_2$ 플라즈마의 영향)

  • Moon, Chang-S.;Chung, Yun-M.;Lee, Ho-Y.;Kim, Yong-M.;Kim, Kab-S.;Gaillard, M.;Han, Jeon-G.
    • Journal of the Korean institute of surface engineering
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    • v.39 no.5
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    • pp.206-209
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    • 2006
  • Indium tin oxide (ITO) films were synthesized on polymer (PES, polyethersulfone) at room temperature by pulsed DC magnetron sputtering. By the control of introducing hydrogen to argon atmosphere, the resistivity of ITO films was obtained at $5.27\;{\times}\;10^{-4}\;{\Omega}{\cdot}cm$ without substrate heating in comparison with $2.65\;{\times}\;10{-3}\;{\Omega}{\cdot}cm$ under hydrogen free condition. ITO film synthesized at Ar condition was changed from amorphous to crystalline. These result from the enhancement of electron temperature in $Ar\;+\;H_2$ plasma, which induces the increase of ionization of target materials and argon. The dominant increase of ions such as In II and O II and neutral Sn I was monitored by optical emission spectroscopy (OES). Thermal energy required for the crystalline film formation is compensated by kinetic energy transfer through ion bombardments to substrate.

Self-Limiting Growth of ZnO Thin Films and Substrate-Temperature Effects on Film Properties (자기제한적 표면반응에 의한 ZnO 박막성장 및 기판온도에 따른 박막특성)

  • Lee, D.H.;Kwon, S.R.;Lee, S.K.;Noh, S.J.
    • Journal of the Korean Vacuum Society
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    • v.18 no.4
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    • pp.296-301
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    • 2009
  • An inductively coupled plasma assisted atomic layer deposition(ICP-ALD) system has been constructed for the deposition of ZnO thin films, and various experiments of ZnO thin films on p-type Si(100) substrates have been carried out to find the self-limiting reaction conditions for the ICP-ALD system under non-plasma circumstances. Diethyl zinc[$Zn(C_2H_5)_2$, DEZn] was used as the zinc precursor, $H_2O$ as the oxidant, and Ar as the carrier and purge gas. At the substrate temperature of $150^{\circ}C$, atomic layer deposition conditions based on self-limiting surface reaction were successfully obtained by series of experiments through the variation of exposure times for DEZn, $H_2O$, and Ar. ZnO deposition was repeated at different substrate temperatures of $90{\sim}210^{\circ}C$. As a result, the thermal process window(ALD window) for ZnO thin films was observed to be $110{\sim}190^{\circ}C$ and the average growth rate was measured to be constant of 0.29 nm/cycle. Properties of the film's microstructure and composition(Zn, O, etc.) were also studied. As the substrate temperature increases, the crystallinity was improved and ZnO(002) peak became dominant. The films deposited at all temperatures were high purity, and the films deposited at high temperatures had the composition ratio between Zn and O closer to one of a stable hexagonal wurtzite structure.

Characteristics of Crystalline Silicon Solar Cells with Double Layer Antireflection Coating by PECVD (결정질 실리콘 태양전지의 이중 반사방지막 특성에 대한 연구)

  • Kim, Jin-Kuk;Park, Je-Jun;Hong, Ji-Hwa;Kim, Nam-Soo;Kang, Gi-Hwan;Yu, Gwon-Jong;Song, Hee-Eun
    • 한국태양에너지학회:학술대회논문집
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    • 2012.03a
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    • pp.243-247
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    • 2012
  • The paper focuses on an anti-reflection (AR) coating deposited by PECVD in silicon solar cell fabrication. AR coating is effective to reduce the reflection of the light on the silicon wafer surface and then increase substantially the solar cell conversion efficiency. In this work, we carried out experiments to optimize double AR coating layer with silicon nitride and silicon oxide for the silicon solar cells. The p-type mono crystalline silicon wafers with $156{\times}156mm^2$ area, 0.5-3 ${\Omega}{\cdot}cm$ resistivity, and $200{\mu}m$ thickness were used. All wafers were textured in KOH solution, doped with $POCl_3$ and removed PSG before ARC process. The optimized thickness of each ARC layer was calculated by theoretical equation. For the double layer of AR coating, silicon nitride layer was deposited first using $SiH_4$ and $NH_3$, and then silicon oxide using $SiH_4$ and $N_2O$. As a result, reflectance of $SiO_2/SiN_x$ layer was lower than single $SiN_x$ and then it resulted in increase of short-circuit current and conversion efficiency. It indicates that the double AR coating layer is necessary to obtain the high efficiency solar cell with PECVD already used in commercial line.

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Fermented red ginseng and ginsenoside Rd alleviate ovalbumin-induced allergic rhinitis in mice by suppressing IgE, interleukin-4, and interleukin-5 expression

  • Kim, Hye In;Kim, Jeon-Kyung;Kim, Jae-Young;Han, Myung Joo;Kim, Dong-Hyun
    • Journal of Ginseng Research
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    • v.43 no.4
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    • pp.635-644
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    • 2019
  • Background: To increase the pharmacological effects of red ginseng (RG, the steamed root of Panax ginseng Meyer), RG products modified by heat process or fermentation have been developed. However, the antiallergic effects of RG and modified/fermented RG have not been simultaneously examined. Therefore, we examined the allergic rhinitis (AR)-inhibitory effects of water-extracted RG (wRG), 50% ethanol-extracted RG (eRG), and bifidobacteria-fermented eRG (fRG) in vivo. Methods: RBL-2H3 cells were stimulated with phorbol 12-myristate-13-acetate/A23187. Mice with AR were prepared by treatment with ovalbumin. Allergic markers IgE, tumor necrosis factor-${\alpha}$, interleukin (IL)-4, and IL-5 were assayed in the blood, bronchoalveolar lavage fluid, nasal mucosa, and colon using enzyme-linked immunosorbent assay. Mast cells, eosinophils, and Th2 cell populations were assayed using a flow cytometer. Results: RG products potently inhibited IL-4 expression in phorbol 12-myristate-13-acetate/A23187-stimulated RBL-2H3 cells. Of tested RG products, fRG most potently inhibited IL-4 expression. RG products also alleviated ovalbumin-induced AR in mice. Of these, fRG most potently reduced nasal allergy symptoms and blood IgE levels. fRG treatment also reduced IL-4 and IL-5 levels in bronchoalveolar lavage fluid, nasal mucosa, and reduced mast cells, eosinophils, and Th2 cell populations. Furthermore, treatment with fRG reduced IL-4, IL-5, and IL-13 levels in the colon and restored ovalbumin-suppressed Bacteroidetes and Actinobacteria populations and ovalbumin-induced Firmicutes population in gut microbiota. Treatment with ginsenoside Rd significantly alleviated ovalbumin-induced AR in mice. Conclusion: fRG and ginsenoside Rd may alleviate AR by suppressing IgE, IL-4, IL-5, and IL-13 expression and restoring the composition of gut microbiota.

Temporal and Spatial Role of Pupal Stage Specific Cuticle Protein in Artogeia rapae (배추흰나비 용기 특이 큐티클 단백질의 시공간적 역할)

  • Shin, Myung-Ja;Park, Jeong-Nam;Seo, Eul-Won
    • Journal of Life Science
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    • v.17 no.2 s.82
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    • pp.223-229
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    • 2007
  • Present study aims to investigate the topical distribution of pupal stage specific cuticle protein and its temporal and spatial role during the wing formation of Artogeia rapae. ArCP27(27 kd cuticle protein) was identified as pupal stage specific cuticle protein in cuticle tissues and has not shown any qualitative differences by local portions of body. ArCP27 maintained constant concentration just after pupal ecdysis to 5-day old pupal stage but thereafter decreased. In fat body, ArCP27 was found in both thoracic and abdominal fat body from the last larval to pupal stage. In wing cuticle, ArCP27 began to find from 5-day old pupal stage. Immunologically ArCP27 in thoracic and abdominal cuticle has the response against the ArCP27 at 5-day old pupa but since then has no response. But the antibody against ArCP27 has reacted to 5- and 7-day old pupal and adult wing protein. $^3H-leucine$ was not incorporated into ArCP27 in 5- and 7-day old thoracic and abdominal cuticle but was incorporated into ArCP27 in 7-day old wing cuticle and adult wing, suggesting that ArCP27 partly participates the wing cuticle formation by the process of digestion and reabsorption of old cuticle.

Preparation of Precision Thin Film Resistor Sputtered by Magnetron Sputtering (IC용 초정밀 박막저항소자의 제조와 특성연구)

  • Ha, H.J.;Jang, D.J.;Moon, S.R.;Park, C.S.;Cho, J.S.;Park, C.H.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1236-1238
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    • 1994
  • TiAlN thin films were prepared by a multi target r.f magnetron sputtering system under different conditions. We have investigated the resistivity and T.C.R. (Temperature Coefficient of Resistance) characteristics of TiAlN films deposited on $Al_2O_3$ and glass substrates by sputtering in an $Ar:N_2$ gas mixture. We used Al and Ti metal as Target Material and $Ar:N_2$ gas as working gas. We varied the partial pressure ratio of $N_2/Ar$ from 0.2/7 to 1.0/6.2 (SCCM). And the R.F power of Ti and Al Target also were varied as 160/240, 200/200 and 240/160(W). In this experiment, we can get the precision thin film resistor with a very low T.C.R. (Temperature Coefficient of Resistance) below 25 ppm ${\Omega}/^{\circ}C$.

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