• Journal of Hydrogen and New Energy
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• v.16 no.4
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• pp.379-385
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• 2005

Effects of Co and Co-P catalysts on the hydrolysis of alkaline $NaBH_4$ solution were investigated. Co and Co-P catalysts were prepared on Cu substrate by electroplating. Hydrogen generation rate of Co-P catalyst was much faster than that of Co catalyst, demonstrating that Co-P had higher intrinsic catalytic activity for the hydrolysis of $NaBH_4$ than Co. Hydrogen generation properties of Co-P catalysts largely depended on cathodic current density and electroplating time because they influenced on the P concentration of the Co-P catalysts. Maximum hydrogen generation rate of Co-P catalyst was 1066 ml/min.g-catalyst in 1 wt.% NaOH + 10 wt.% $NaBH_4$ solution at $20^{\circ}C$, which was obtained at cathodic current density of $0.01\;A/cm^2$ for 130 s.

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.863-868
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• 2009

New spiro[fluorene-7,9′-benzofluorene]-based blue host material, 5-phenyl-spiro[fluorene-7,9′-benzofluorene] (BH-1P), was successfully prepared by reacting 5-bromo-spiro[fluorene-7,9′-benzofluorene] (1) with phenyl boronic acid through the Suzuki reaction. 5-(N,N-Diphenyl)amino-spiro[fluorene-7,9′-benzofluorene] (BH-1DPA) and diphenyl-[4-(2-[1,1;4,1]terphenyl-4-yl-vinyl)-phenyl]amine (BD-1) were used as dopant materials. 2,5-Bis-(2',2"- bipyridin-6-yl)-1,1-diphenyl-3,4-diphenylsilacyclopentadiene (ET4) and Alq3 were used as electron transfer materials. Their UV absorption, photoluminescence and thermal properties were examined. The blue OLEDs with the configuration of ITO/DNTPD/$\alpha$-NPD/BH-1P:5% dopant/$Alq_3$ or ET4/LiF-Al prepared from the BH-1P host and BH-1DPA and BD-1 dopants showed a blue EL spectrum at 452 nm at 10 V and a luminance of 923.9 cd/$m^2$ with an efficiency of 1.27 lm/W at a current density of 72.57 mA/$cm^2$.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.2
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• pp.69.2-69.2
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• 2021

We present the discovery of rare active galactic nuclei (AGNs) in nearby (z<0.05) compact elliptical galaxies (cEs) located in isolated environments. Using spectroscopic data from the Sloan Digital Sky Survey (SDSS) Data Release 12, four AGNs were identified based on the optical emission-line diagnostic diagram. SDSS optical spectra of AGNs show the presence of distinct narrow-line emissions. Utilizing the black hole (BH) mass-stellar velocity dispersion scaling relation and the correlation between the narrow L([OIII])/L(Hβ) line ratio and the width of the broad Hα emission line, we estimated the BH masses of the cEs to be in the range of 7×10⁵-8×10⁷ solar mass. The observed surface brightness profiles of the cEs were fitted with a double Sérsic function using the Dark Energy Camera Legacy Survey r-band imaging data. Assuming the inner component as the bulge, the K-band bulge luminosity was also estimated from the corresponding Two Micron All Sky Survey images. We found that our cEs follow the observed BH mass-stellar velocity dispersion and BH mass-bulge luminosity scaling relations, albeit there was a large uncertainty in the derived BH mass of one cE. In view of the observational properties of BHs and those of the stellar populations of cEs, we discuss the proposition that cEs in isolated environments are bona fide low-mass early-type galaxies (i.e., a nature origin).

• Journal of the Korean Chemical Society
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• v.49 no.6
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• pp.613-616
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• 2005

• 한국전기화학회:학술대회논문집
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• 2004.06a
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• pp.129-134
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• 2004

문헌 연구를 통해 최적의 수소저장물질의서 수소저장 효율, 물질의 안정성 및 경제성이 우수한 나트륨붕소수소화물($NaBH_4$, sodium borohydride)을 선정하여, 소형연료전지용 수소저장시스템에 대한 다양한 특성을 조사하였다. $NaBH_4$의 기초 물성 조사를 위해 수소 발생 능력, 용해도, 수소 비발생 등의 실험을 수행하였으며 다양한 촉매의 특성비교는 물론 수소저장시스템의 설계시 핵심적으로 고려할 수 있는 Key factor의 특성을 파악하였다.

• Honam Mathematical Journal
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• v.34 no.4
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• pp.585-596
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• 2012

The notions of a $\mathcal{N}$-subalgebra, a (strong) $\mathcal{N}$-ideal of BH-algebras are introduced, and related properties are investigated. Characterizations of a coupled $\mathcal{N}$-subalgebra and a coupled (strong) $\mathcal{N}$-ideals of BH-algebras are given. Relations among a coupled $\mathcal{N}$-subalgebra, a coupled $\mathcal{N}$-ideal and a coupled strong $\mathcal{N}$ of BH-algebras are discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.3
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• pp.255-259
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• 1998

Sixteen Friesian Cows were allocated equally into 4 groups in a $4{\times}4$ Latin square design to evaluate the effects of utilizing bean by-products on the feed intake and milk production. Cows were fed on 4.5% of their body weight fresh alfalfa; the remainder of their requirements were covered by one of 4 experimental concentrate treatments: 1) commercial concentrate (CC), 2) 70% CC + 30% bean hulls (BH), 3) 70% CC + 30% Polished bean (PB) and 4) 70% CC+ 15% BH + 15% PB. Results showed that the inclusion of bean hulls at 30% improved (p<0.05) milk yield, 4% fat corrected milk yield, feed conversion ratio and fat percent of the milk over the other treatments. Feeding cows on a commercial concentrate plus 30% BH or 30% PB or 15% from each of BH and PB decreased the cost of feed per kg milk by 13.6, 2.5 and 1.3 %, respectively, lower than those fed on the commercial concentrate.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.35.1-35.1
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• 2012

Determining the virial factor of the broad-line region (BLR) gas is crucial in calibrating AGN black hole mass estimators, since the measured line-of-sight velocity needs to be converted into the representative velocity of the BLR gas. The unknown virial factor has been empirically calibrated based on the $M_{BH}-{\sigma}_*$ relation of non-AGN galaxies, but the claimed values are different by a factor of 2 in recent studies. We investigate the origin of the difference by measuring the $M_{BH}-{\sigma}_*$ relation using the most updated nearby galaxy sample, and explore the dependence of the virial factor on the various fitting methods. We find that the discrepancy is mostly caused by the sample bias while the difference stemming from various regression methods is marginal. Based on the best-determined virial factor, we present the updated $M_{BH}-{\sigma}_*$ relation of local active galaxies.

• Proceedings of the Korean Society for Cognitive Science Conference
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• 2000.05a
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• pp.287-291
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• 2000

후천성 한글 난동증 환자인 BHS를 대상으로 두 개의 과제를 이용하여 어휘 처리에 있어서의 구체성 효과(concreteness effect)를 조사하였다. 어휘판단과제를 실시한 결과 BHS는 구체어에 비해 추상어에 대해서 상대적으로 많은 오류를 나타내었다. 그러나 비단어에 대한 어휘 판단은 비교적 정확했다. 음독과제를 실시한 결과 어휘판단과제와 동일하게 구체어에 대한 음독수행은 매우 저조하였다. BHS는 구체어보다 추상어에 대한 처리의 손상 정도가 심한 것으로 판단된다. 이러한 결과는 심성어휘집에 있어서 구체어와 추상어가 독립적으로 표상되어 있을 가능성을 시사한다. 또한 BHS의 비단어에 대한 음독이 거의 불가능하였던 것은 자소-음소 변환 경로(조합경로)의 심한 손상에 기인한 것으로 생각된다.

• Journal of the Korean Mathematical Society
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• v.51 no.4
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• pp.791-815
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• 2014

We show amongst other that if $f,g:[a,b]{\rightarrow}\mathbb{C}$ are two functions of bounded variation and such that the Riemann-Stieltjes integral $\int_a^bf(t)dg(t)$ exists, then for any continuous functions $h:[a,b]{\rightarrow}\mathbb{C}$, the Riemann-Stieltjes integral $\int_{a}^{b}h(t)d(f(t)g(t))$ exists and $${\int}_a^bh(t)d(f(t)g(t))={\int}_a^bh(t)f(t)d(g(t))+{\int}_a^bh(t)g(t)d(f(t))$$. Using this identity we then provide sharp upper bounds for the quantity $$\|\int_a^bh(t)d(f(t)g(t))\|$$ and apply them for trapezoid and Ostrowski type inequalities. Some applications for continuous functions of selfadjoint operators on complex Hilbert spaces are given as well.