• The Bulletin of The Korean Astronomical Society
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• v.42 no.1
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• pp.38.2-38.2
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• 2017

We present the observational study toward the multiple outflows around $LkH{\alpha}$ 234 star formation region. The high-resolution, near-IR spectral mapping using the Immersion Grating Infrared Spectrograph (IGRINS) allowed us to distinguish at least four separate outflows with the molecular hydrogen ($H_2$) and forbidden iron ([Fe II]) emission lines. The outflow associated with the radio continuum source VLA 3B is detected in both H2 and [Fe II] emission, while the outflows driven by MM 1, VLA 2 sources were only detected in $H_2$, indicating the different physical conditions of outflows. We confirm the axis of VLA 3B jet, the position angle of ${\sim}240^{\circ}$. We firstly identified the redshifted, near-IR H2 outflow associated with VLA 2, which is coincident with the previous detections of $H_2O$ masers. From the $H_2$ line ratios, we interpret the gas properties of the shock excited blue- and redshifted components, and UV excited surrounding photodissociation region. We also discuss the origin of the high-velocity (|VLSR| > $150km\;s^{-1}$) $H_2$ emission.

• Journal of Hydrogen and New Energy
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• v.28 no.2
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• pp.144-149
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• 2017

A proton-conducting bisphenylpropaned sulfonated fluorinated blockcopolymer (BPSFBC) was synthesized. Five kinds of polymer electrolyted composite membranes were preparated by incorporating silica ($SiO_2$) with various weight ratio. And their characteristics were investigated by FT-IR (fourier transform infrared), $^1H-NMR$ ($^1H$ nuclear magnetic resonance), TGA (thermogravimetric analysis), water uptake, FE-SEM (field emission scanning electron microscopes), and ion conductivity properties. The water uptake and ion conductivity were increased until 9 wt% $SiO_2$, and then decreased. The maximum proton conductivity equal to $52mScm^{-1}$ was measured for the BPSFBC/$SiO_2$-9 composite membrane at $90^{\circ}C$ and 100% relative humidity. From the measured results, it is distinct that the manufactured composite membrane BPSFBC/$SiO_2$-9 can be considered as a polymer membrane suitable for a fuel cell electrolyte.

• Clean Technology
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• v.21 no.4
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• pp.271-277
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• 2015

A photocatalyst which mixed by the commercialized P25-TiO₂ and a synthesized Ag_xO was used in an appropriate weight ratio to effectively produce hydrogen gas in this study. The Ag_xOs were synthesized with the conventional sol-gel method, and tetramethylammonium hydroxides were added at the synthesis process in order to stabilize the solutions, and then the solutions were heat-treated at the temperatures of -5, 25, and 50 ℃, resulted to obtain the three types of silver oxides. Physicochemical properties of the synthesized Ag_xOs were identified through X-ray diffraction analysis (XRD), scanning emission microscopy (SEM), ultraviolet-visible spectroscopy, and X-ray photoelectron spectroscopy (XPS). In the photolysis results of water/methanol (weight ratio 1:1) solution, the mixture of P25-TiO₂/Ag_xO exhibited a significantly higher hydrogen gases evolution, compared to that of pure P25-TiO₂. Additionally, the addition of H₂O₂ as an supplement oxidant and in Ag_xO synthesized at 50 ℃ improved the hydrogen production efficiency. In particular, the emitted hydrogen gases reached to 13,000 μmol during 8 hours when a mixed catalyst, Ag_xO of 0.1 g and P25-TiO₂ of 0.9 g, were used.

• Proceedings of the KIEE Conference
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• 1998.11c
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• pp.895-897
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• 1998

The optical spectra of microwave plasma by four kinds of gases($N_2$, $N_2-CH_4$, $H_{2}-CH_{4}$ and Air-$CH_4$) have been measured for investigating 388.4[nm] peak which has the same intensity as $H_{\alpha}$(656.4[nm]) peak. A 388.4[nm] peak by $N_2$ plasma, $N_{2}-CH_{4}$ plasma and Air-$CH_4$ plasma may be CN peak because it is with 337.1, 357.8 and 316.0[nm] peaks by $N_2$. And a 388.4[nm] peak by $H_{2}-CH_{4}$ plasma without by $N_2$ 337.1, 357.8 and 316.0[nm] peaks may be CH peak. In the investigation results for optical spectra by $H_{2}-CH_{4}$ plasma and $H_{2}-CH_{4}-O_{2}$ plasma, the density of hydrogen atom was increased because oxygen decompose hydrogen molecules in $H_{2}-CH_{4}$ plasma with oxygen. These hydrogen atom decompose $CH_4$ and increase CH radical. And the crystalline of deposited diamond was good and the growth rate increased.

• BMB Reports
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• v.39 no.2
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• pp.145-149
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• 2006

To analyze the effect of Maltol on the apoptosis of Human Neuroblastoma Cells (SH-SY5Y) treated by free radical which was generated from Hydrogen Peroxide ($H_2O_2$), flow cytometry analysis on Phosphatidylserine (PS) inverting percentage was applied to determine the apoptosis. MTT (3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) assay was employed to analyze the cell viability. DNA electrophoresis was used to detect DNA fragmentation. Moreover intracellular calcium of concentration ($[Ca^{2+}]_i$) was measured by fluorescence emission. Flow cytometry analysis on the function of mitochondria and Western blto analysis of NF-${\kappa}B$. The results showed that the pretreatment with maltol for 2 hours could prevent the $H_2O_2$-induced apoptosis. Maltol could reduce the inverting percentage of PS, DNA fragmentation and $[Ca^{2+}]_i$, and enhance the cellular function of mitochondria. NF-${\kappa}B$ activated by $H_2O_2$ is reduced. The experiments suggest that maltol could effectively inhibit the apoptosis induced by $H_2O_2$. As a novel anti-oxidant, maltol is a new promising drug in protecting the neurological cells from the damage by free radical.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.5
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• pp.448-454
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• 2009

Hydrogen was produced from water plasma excited in high frequency (HF) inductively coupled tubular reactor. Mass spectrometry was used to monitor gas phase species at various process conditions, Water dissociation rate depend on the process parameters such as ICP power, $H_{2}O$ flow-rate and process pressure, Water dissociation percent in ICP reactor decrease with increase of chamber pressure, while increase with increase of ICP power and $H_{2}O$ flow rate. The effect of $CH_4$ gas addition to a water plasma on the hydrogen production has been studied in a HF ICP tubular reactor. The main roles of $CH_4$ additive gas in $H_{2}O$ plasma are to react with 0 radical for forming $CO_x$ and CHO and resulting additional $H_2$ production. Furthermore, $CH_4$ additives in $H_{2}O$ plasma is to suppress reverse-reaction by scavenging 0 radical. But, process optimization is needed because $CH_4$ addition has some negative effects such as cost increase and $CO_x$ emission.

• Journal of Hydrogen and New Energy
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• v.21 no.6
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• pp.519-525
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• 2010

Ethanol was used as reductant to remove $NO_x$ over Ag/$Al_2O_3$ catalyst via SCR from stationary emission source. Among the tested hydrocarbon reductants, ethanol showed highest de-$NO_x$ performance over the Ag/$Al_2O_3$ catalyst. De-$NO_x$ efficiency of about 83% was obtained in the condition of GHSV 20,000 $hr^{-1}$, $NO_x$ 200 ppm, CO 200 ppm, $O_2$ 13%, $H_2O$ 5% and mole ratio of ethanol/$NO_x$ = 2 between temperature of $300^{\circ}C$ and $400^{\circ}C$. While $SO_2$ presence in the $NO_x$ exhaust suppressed the catalytic activity, catalyst with acid (0.7% $H_2SO_4$) treatment of catalyst showed higher catalytic activity, where In-Situ DRIFT showed S presence over catalyst surface was increased after acid treatment of catalyst. From in-situ DRIFT and SCR results, it was concluded that sulfur presence over the surface of Ag/$Al_2O_3$ catalyst was the dominant factor to control the de-$NO_x$ reaction yield via HC-SCR from the exhausted gas including $SO_2$.

• Journal of the Korean Vacuum Society
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• v.16 no.6
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• pp.463-467
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• 2007

Structure and optical properties of ZnO epilayers grown on oxygen- and hydrogen-plasma treated sapphire substrates by plasma-assisted molecular beam epitaxy (denoted as samples A and B, respectively) have been investigated by various techniques. The crystal quality and structural properties of the surface for the ZnO epilayers were investigated by high-resolution X-ray diffraction and atomic force microscope. For investigating the optical properties of excitonic transition of ZnO, we carried out photoluminescence experiments as a function of temperature. The free exciton, bound exciton emission and their phonon replicas were investigated as a function of temperature from 10 to 300 K, and the intensity of excitonic PL peak emission from the sample A is found to be higher than that of sample B. From the results, we found that sample A has better crystal structure quality and optical properties as compared to sample B. The number of oxygen vacancies may be decreased in sample A, resulting in an enhancement of the crystal quality and a higher intensity of excitonic emission band as compared to sample B.

• The Bulletin of The Korean Astronomical Society
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• v.35 no.1
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• pp.68.1-68.1
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• 2010

We focus on two Galactic molecular clouds that are located in wholly different environments and both are observed by FIMS instrument onboard STSAT-1. The Draco cloud is known as a translucent molecular cloud at high Galactic latitude. The FUV spectra show important ionic lines of C IV, Si IV+O IV], Si II* and Al II, indicating the existence of hot and warm interstellar gases in the region. The enhanced C IV emission inside the Draco cloud region is attributable to the turbulent mixing of the interacting cold and warm/hot media, which is supported by the detection of the O III] emission line and the $H{\alpha}$ feature in this region. The Si II* emission covers the remainder of the region outside the Draco cloud, in agreement with previous observations of Galactic halos. Additionally, the H2 fluorescent map is consistent with the morphology of the atomic neutral hydrogen and dust emission of the Draco cloud. In the Aquila Rift region near Galactic plane, FIMS observed that the FUV continuum emission from the core of the Aquila Rift suffers heavy dust extinction. The entire field is divided into three sub-regions that are known as the- "halo," "diffuse," and "star-forming" regions. The "diffuse" and "star-forming" regions show various prominent H2 fluorescent emission lines, while the "halo" region indicates the general ubiquitous characteristics of H2. The CLOUD model and the FUV line ratio are included here to investigate the physical conditions of each sub-region. Finally, the development of an infrared imaging system known as the MIRIS instrument onboard STSAT-3 is briefly introduced. It can be used in WIM studies through $Pa{\alpha}$ observations.

• Clean Technology
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• v.23 no.3
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• pp.294-301
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• 2017

Air pollution associated with the $NO_x$ emission from the ship engines is becoming one of the major environmental concerns these days. As the regulations on ship pollutants are strengthened, the wet absorption method, for controlling complex pollutants in a confined space, has the advantage of simultaneously removing various pollutants, but the low solubility of nitrogen monoxide is drawback. In this study, for improving existing denitrification scrubber system, NO oxidation process by hydroxyl radical produced from irradiating UV light on $H_2O_2$ is suggested and the $H_2O_2$ decomposition rates and hydroxyl radical quantum yields were measured to find the optimum condition of $H_2O_2$ photolysis reaction. As a result, the optimum quantum yield and photolysis rate of $H_2O_2$ were 0.8798, $0.6mol\;h^{-1}$ at 8 W, 2 M condition, and oxidation efficiency of 1000 ppm NO gas was 40%. In batch system, NO removal efficiency has a range of 65.0 ~ 67.3% according to input gas concentration of 100 ~ 1500 ppm. This results indicate that the scrubber system using hydrogen peroxide photolysis can be applied as air pollution prevention facility of ship engines.