• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.47.1-47.1
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• 2012

Given high accretion rates close to the Eddington limit, narrow-line Seyfert 1 galaxies (NLS1) are arguably the most important AGN subclass in investigating the origin of the black hole mass-galaxy stellar velocity dispersion ($M_{BH}-{\sigma}$) relation. Currently, it is highly debated whether NLS1s are offset from the local $M_{BH}-{\sigma}$ relation. The controversy mainly comes from the fact that the [OIII] line width has been used as a proxy for stellar velocity dispersion due to the difficulty of measuring stellar velocity dispersion in NLS1s. Using the SDSS spectra of a sample of 105 NLS1, we performed multi-component fitting analysis to separate stellar absorption lines from strong AGN [FeII] complex in order to directly measure stellar velocity dispersion. We will present the result of decomposition analysis and discuss whether NLS1s follow the same $M_{BH}-{\sigma}$ relation based on the direct measurements of stellar velocity dispersion.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.08a
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• pp.37-44
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• 2004

Automotive company has been endeavoring to develop high strength steels to get higher fuel efficiency of car since the oil shortage in 1970s and to cope with the recent strict environmental regulation. Outer panels(Hood, Roof, Door and Fender) for automobile require higher dent resistance. Bake-hardenable(BH) steels are known as useful for their high deep drawability and high dent resistance. Recently BH steels are increasingly adapted for outer panel use due to their high drawability and high dent resistance. In this study effect of temper rolling on formability (textures, r value) and bake hardenability is investigated fur improving characteristic of bake-hardenable steels.

• The Pure and Applied Mathematics
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• v.19 no.3
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• pp.251-262
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• 2012

Based on the theory of a falling shadow which was first formulated by Wang([14]), a theoretical approach of the ideal structure in BH-algebras is established. The notions of a falling subalgebra, a falling ideal, a falling strong ideal, a falling $n$-fold strong ideal and a falling translation ideal of a BH-algebra are introduced. Some fundamental properties are investigated. Relations among a falling subalgebra, a falling ideal and a falling strong ideal, a falling $n$-fold strong ideal are stated. A relation between a fuzzy subalgebra/ideal and a falling subalgebra/ideal is provided.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.80-80
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• 2014

Dynamics of a globular cluster (GC) is dominated by behaviors of high-mass components such as neutron stars or black holes (BHs). Massive components in a cluster are segregated into the cluster core and some of them are ejected by dynamical interactions. In this study, we perform N-body simulations of GCs adapting two BH mass components, $10M_{\odot}$ and $20M_{\odot}$. Previous studies which mostly assume single-mass BHs suggested a rapid collapsing and escaping of BHs. A cluster with a two-component BH mass spectrum, however, retains a large fraction of $10M_{\odot}$ BHs longer. In addition to their roles in cluster dynamics, massive components in binaries are one of important sources of gravitational waves (GWs). We investigate properties of BH binaries escaped from the cluster and discuss their implications for GW detection.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2961-2966
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• 2010

Reduction of carbonyl compounds such as aldehydes, ketones, $\alpha,\beta$-unsaturated enals and enones, $\alpha$-diketones and acyloins was carried out readily with $NaBH_3CN$ in the presence of wet $SiO_2$ as a neutral media. The reactions were performed at solvent-free conditions in oil bath (70 - $80^{\circ}C$) or under microwave irradiation (240 W) to give the product alcohols in high to excellent yields. Regioselective 1,2-reduction of conjugated carbonyl compounds took place in a perfect selectivity without any side product formation.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.80.1-80.1
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• 2012

The $2.5-5.0{\mu}m$ spectrum of AGN was poorly understood due to the atmosphere effect beyond $2{\mu}m$. Nevertheless, the $2.5-5.0{\mu}m$ range includes several important lines, such as $Br{\beta}$ ($2.63{\mu}m$), $Br{\alpha}$ ($4.05{\mu}m$), PAH (3.3${\mu}m$) and many molecular or atomic lines. We compile $2.5-5.0{\mu}m$ spectra of 79 AGNs and QSOs from infrared camera (IRC) on AKARI infrared astronomy satellite. Our $2.5-5.0{\mu}m$ spectra will provide an access to full wavelength spectra of AGNs for the first time. Moreover, we present the Brackett line properties, FWHMs and luminosities, of AGNs. Using these Brackett line properties, we derive new black hole (BH) mass estimators. The new BH mass estimators using NIR hydrogen lines will be very useful to estimate BH mass of dusty red AGNs in the future.

• Transactions of Materials Processing
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• v.10 no.1
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• pp.30-34
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• 2001

The magnetic and metallurgical characteristics of Mischmetal(MM) -Ferroboron (FeB) Permanent magnets have been investigated by X-ray diffractometer, scanning and transmission electron microscope and vibrating sample magnetometer under hot-pressing and die-upsetting process. The best magnetic properties obtained in these studies were $H_c$=5.8 kOe, $B_r$=5.0 kG with $(BH)_{max}=7.6 MGOe for melt-spun ribbons, $H_c$=3.0 kOe, $B_r$=4.6 kG with $(BH)_{max}$=2.9 MGOe for hot-pressed magnets and $H_c$=1.8 kOe, $B_r$=5.5 kG with $(BH)_{max}$=4.1 MGOe for die-upset magnets. The higher magnetic properties in die-upset magnets were resulted from alignment of the c-axis along the die-upsetting direction.

• Journal of Soil and Groundwater Environment
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• v.12 no.4
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• pp.35-53
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• 2007

Geochemical and isotope studies on the groundwater system of the Youngcheon area were carried out. Most groundwaters belong to Ca-$HCO_3$ and Ca-$SO_4$ types and some groundwaters belong to Na-$HCO_3$ type. Geochemical characteristics of these groundwaters were mainly affected by their basement rocks around the boreholes. High $SO_4$ content of groundwater is the result of reaction with sulfate or sulfide minerals in the host rock. Ca was originated from the carbonate minerals in the sedimentary rock. After the groundwater was saturated with calcite, the Na-$HCO_3$ type groundwaters were evolved by the reaction with plagioclase for a relatively long residence time. This explanation was supported by low tritium contents of Na-$HCO_3$ type groundwaters. ${\delt}a^{18}O$ and ${\delta}D$ data indicate that the groundwaters are of meteoric water origin and there was no difference between the various types of waters. Grondwaters from the boreholes BH-1, BH-9 and BH-12 showed the geochemical and isotopic characteristics of deep groundwater. Most borehole groundwaters except them did not show the systematic geochemical variations with sampling depth indicating that the shallow and deep groundwaters were mixed with each other throughout the study area. The results of water quality analysis indicate that the study area is highly contaminated by the introduction of agricultural sewage.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.694-706
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• 2017

This study evaluated the protein recovery, functional properties and biological activity of isolate processed water (IPW) generated in the preparation of protein isolates from fish roes (BH, bastard halibut Paralichthys olivaceus; ST, skipjack tuna Katsuwonus pelamis; YT, yellowfin tuna Thunnus albacares) by an isoelectric solubilization and precipitation process. The IPWs contained 2.7-5.4 mg/mL of protein, and the protein losses were 8-21% (P<0.05). The form capacity of IPW-3 for BH and ST, and IPW-4 for YT was 155, 194, and 164%, respectively. The emulsifying activity index ($27-43m^2/g$) of the YT-IPWs was the strongest, followed by ST ($7-29m^2/g$) and BH ($10-19m^2/g$). The 2,2-diphenyl-1-picrylhydrazyl scavenging activities of IPW-1 and -3 were higher than those of IPW-2 and -4. The 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid scavenging activity ($IC_{50}$, mg/mL) of IPW-2 and -4 was 0.03 mg/mL for BH, 0.04-0.08 mg/mL for ST, and 0.04-0.07 mg/mL for YT. BH IPW-3 had the strongest reducing power (0.41 mg/mL) and superoxide dismutase-like activity (1.68 mg/mL). The angiotensin-I converting enzyme inhibitory activity of IPW-3 was the highest for ST (1.52 mg/mL), followed by BH and YT. The common predominant amino acids in the IPWs were the essential amino acids Val, Leu, Lys, and Arg and the non-essential amino acids Ser, Glu, and Ala.

• Clean Technology
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• v.29 no.2
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• pp.79-86
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• 2023

The homogeneous catalyst, Ru-MACHO-BH, selectively performs hydrogenation reactions only on the carbonyl group of α, β-unsaturated aldehyde compounds with extremely high reactivity and selectivity. However, the hydrogenation of α, β-unsaturated aldehydes involves a heterogeneous Diels-Alder reaction, resulting in the formation of significant amounts of byproducts, such as dimers. In this study, we used the Ru-MACHO-BH catalyst (Carbonyl hydrido (tetrahydroborato) [bis (2-diphenyl phosphino ethyl) amino] ruthenium(II)) to selectively hydrogenate the carbonyl group of a specific type of α, β-unsaturated aldehyde called methacryl aldehyde, leading to the synthesis of methallyl alcohol. Simultaneously, we applied diols to inhibit the formation of byproducts. The results demonstrate that monoethylene glycol can significantly reduce the formation of diols. Based on these results, we effectively suppressed the formation of dimers containing vinyl groups in methacryl aldehyde by using hydroquinone, which can efficiently inhibit the chemical interaction of vinyl groups. Consequently, the conversion rate of methacryl aldehyde was increased. Ultimately, by reducing the amount of the expensive homogeneous catalyst Ru-MACHO-BH to 1/10, we achieved a selectivity of over 90% and a yield of over 80% for the desired product, methallyl alcohol. These results provide a method to minimize yield reduction while reducing the usage of expensive catalysts, thereby improving cost-effectiveness. We expect that the reaction could be applied to various kinds of selective hydrogenation and has been successfully run on an industrial scale.