• Journal of Environmental Health Sciences
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• 제34권3호
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• pp.240-246
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• 2008

The purpose of this study was to gain basic information on the characteristics of $CO_2$ adsorption in relation to $Na_2CO_3$, $K_2CO_3$, $Li_2CO_3$-impregnated activated carbon in a Fixed Bed Reactor. From the results of this study the following conclusions were made: $Na_2CO_3$, $K_2CO_3$, $Li_2CO_3$-impregnated activated carbon had a longer breakthrough time and more enhanced adsorption capacity than activated carbon alone. When tested with isothermal adsorption and tested for $CO_2$ adsorption the amount of $CO_2$ adsorbed varied with temperature, $CO_2$ inlet concentration, gas flow rate, aspect ratio, etc. Based on the results, when Langmuir, Freundlich and Dubinin-Polanyi adsorption isotherms were used for linear regression of isothermal adsorption data, Langmuir adsorption isotherm was the most suitable. And, the optimum condition for $Na_2CO_3$ and $K_2CO_3$ impregnated activated carbon make-up was 1N and $Li_2CO_3$ was 0.1N. It could be concluded that adsorption capacity was decreased with adsorption temperature and increased gas concentration. When the aspect ratio (L/D) was varied 0.5, 1.0 and 2.0, the significant drop of adsorption amount was observed below 1.0 and breakthrough time was shortened with gas flow rate.

• Journal of Veterinary Science
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• 제22권1호
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• pp.12.1-12.11
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• 2021

Background: Bats have been considered natural reservoirs for several pathogenic human coronaviruses (CoVs) in the last two decades. Recently, a bat CoV was detected in the Republic of Korea; its entire genome was sequenced and reported to be genetically similar to that of the severe acute respiratory syndrome CoV (SARS-CoV). Objectives: The objective of this study was to compare the genetic sequences of SARS-CoV, SARS-CoV-2, and the two Korean bat CoV strains 16BO133 and B15-21, to estimate the likelihood of an interaction between the Korean bat CoVs and the human angiotensin-converting enzyme 2 (ACE2) receptor. Methods: The phylogenetic analysis was conducted with the maximum-likelihood (ML) method using MEGA 7 software. The Korean bat CoVs receptor binding domain (RBD) of the spike protein was analyzed by comparative homology modeling using the SWISS-MODEL server. The binding energies of the complexes were calculated using PRODIGY and MM/GBGA. Results: Phylogenetic analyses of the entire RNA-dependent RNA polymerase, spike regions, and the complete genome revealed that the Korean CoVs, along with SARS-CoV and SARS-CoV-2, belong to the subgenus Sarbecovirus, within BetaCoVs. However, the two Korean CoVs were distinct from SARS-CoV-2. Specifically, the spike gene of the Korean CoVs, which is involved in host infection, differed from that of SARS-CoV-2, showing only 66.8%-67.0% nucleotide homology and presented deletions within the RBD, particularly within regions critical for cross-species transmission and that mediate interaction with ACE2. Binding free energy calculation revealed that the binding affinity of Korean bat CoV RBD to hACE2 was drastically lower than that of SARS-CoV and SARS-CoV-2. Conclusions: These results suggest that Korean bat CoVs are unlikely to bind to the human ACE2 receptor.

• Journal of the Korean Vacuum Society
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• 제4권1호
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• pp.51-59
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• 1995

(001)방향 GaAs 기판과 Si/Co 박막의 계면반응 및 상평형에 관한 연구를 300-$700^{\circ}C$ 열처리 구간에서 행하였다. 반응에 의한 상전이 과정은 glancing angle X-ray diffraction(GXRD), Auger electron spectroscopy(AES) 및 cross-sectional transmission electron microscopy(GXRD), Auger electron spectroscopy(AES) 및 corss-sectional transmission electron microscopy(XTEM)을 이용하여 분석하였다. Si/Co/GaAs계의 계면반응에서 Co는 $380^{\circ}C$에서 GaAs 기판 및 Si와 반응하여 Co2GaAs과 Co2Si상을 형성하였다. $420^{\circ}C$에서 열처리 후, Co층은 모두 소모되었으며 단면구조는 Si/CoSi/CoGa(CoAs)/Co2GaAs/GaAs으로 전이되었다. $460^{\circ}C$까지 온도를 올려 계속적인 반응을 일으키면 CoGa와 CoAs이 분해되면서 CoSi가 성장하였고, $600^{\circ}C$에서는 Co2GaAs마저 분해되고 CoSi상이 성장하여 GaAs와 계면을 형성하였다. CoSi와 GaAs사이의 계면은 $700^{\circ}C$의 고온까지 안정하였으며 이러한 계면반응 결과는 계산에 의하여 구한 Si-Co-Ga-As 4원계 상태도로부터 이해될 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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• pp.551-555
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• 2006

A new type of diffractive spatial optical modulators, named SOM, has been developed by Samsung Electro-Mechanics for projection display and other applications. A laser display in full HD format $(1920{\times}1080)$ was successfully demonstrated by using prototype projection engines having SOM devices, signal processing circuits, and projection optics.

• Korean Journal of Chemical Engineering
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• 제39권
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• pp.1028-1035
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• 2022

MgO-based sorbents were prepared by impregnation with K₂CO₃ at different loadings. This study examined the CO₂ absorption and regeneration properties of MgO-based sorbents at various pressures. The CO₂ capture capacity of the PMI-30 sorbent increased to 204.4 mg CO₂/g sorbent with increasing absorption pressure through CO₂ absorption by MgO itself and K₂CO₃ by generating structures, such as MgCO₃·3H₂O and K₂Mg(CO₃)₂. However, no KHCO₃ phase was observed after CO₂ absorption at 1, 10, and 20 atm. The CO₂ capture capacity of the MgO and PMI-10, 20, 30, and 40 sorbents was the 94.6, 129.9, 156.6, 204.4, and 239.4 mg CO₂/g sorbent, respectively. The CO₂ capture capacity of MgO in the PMI sorbent was relatively constant regardless of the decreasing MgO content and increasing K₂CO₃ content. The CO₂ absorption ability of MgO was calculated by substracting theoretical CO₂ capture capacity of K₂CO₃ from the total capacity of sorbents. The TPD experiment performed at 1 atm after CO₂ absorption at 20 atm showed that the regeneration temperature of the PMI sorbents differed according to the K₂CO₃ loading.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 한국방사성폐기물학회 2018년도 춘계학술논문요약집
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• pp.206-207
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• 2018

• Journal of Powder Materials
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• 제3권2호
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• pp.97-103
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• 1996

The densification of the compacts of pure Co, Fe+50%.Co and Fe+25% Co sintered under H$_2$ gas or in vacuum was investigated. The effects of AL, Nb, Ti, and V additions on the densification were also studied. The sintered compact of Co was fully-dense when the density of the compact was lower than $Dg^c$. However, above $Dg^{c}$, it was never fully-dense regardless of sintering atmosphere, temperature, and time. The densification of sintered compacts of Fe-50% Co and Fe-25% Co were always incomplete. While the addition of AL made all compacts fully-dense, the addition of Ti was effective for the compacts of Co and Fe-25% Co. V was effective only for the Fe-25% Co. These results tell us that the particle size of Co powder, the amount of Fe, and the amount of additives forming stable oxides play on important role for the complete densification. Therefore it is desirable to reduce or eliminate the equilibrium pressure of H$_{2}$O or CO in isolated pores to obtain a fully-dense sintered compact.

• Knowledge Management Research
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• 제15권2호
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• pp.129-145
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• 2014

As a community of practice (CoP) is known to facilitate team learning, it is increasingly important to understand the mechanisms of CoP, thereby enabling organizations to fully utilize it and optimize its benefits. To explain how CoP improves organizational performance, we focus on its effects on social capital and knowledge management activities, and propose a research model suggesting that shared goals and trust in CoP improve its performance through knowledge integration. Our analysis uses structural equation modeling, with field data collected from 372 members of 46 CoPs in three companies; the analysis validates our research model. Our findings also suggest that CoP diversity can strengthen the link between knowledge integration and CoP performance.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 추계학술대회 초록집
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• pp.177.1-177.1
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• 2011

온실가스 감축에 대응하기 위해서 CCS기술이 지구온난화 문제를 해결하는 중요한 기술로 부각되고 있다. $CO_2$ 포집기술 중 습식법에는 대표적으로 아민, 암모니아, $K_2CO_3$와 같은 흡수제를 이용한 연구가 진행되고 있다. 본 연구에서는 $CO_2$ 포집기술 중 하나인 $K_2CO_3$ 수용액을 이용하여 Bench급 $CO_2$ 포집설비에 대한 성능을 파악하기 위한 일환으로 15% $CO_2$를 공급하여 $CO_2$ 포집 안정화 시험을 진행하였다. 압력변화 및 단수 변화를 하여 실험을 진행하였고, 흡수탑 후단의 $CO_2$ 농도를 측정하여 $CO_2$ 포집 성능을 파악하였다.

• Bulletin of the Korean Chemical Society
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• 제15권6호
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• pp.436-442
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• 1994

Heterobimetallic complexes have a donor-accepter metal-metal bond in which two electrons from the electron-rich metal moiety are donated to the other electron-deficient one. Based on the competition reactions, Cotton-Kraihanzel force constants, ν(CO)IR band resolution and the relative nucleophilicity comparison of the donor ligands, the following relative ligating ability of the donor ligands toward $M(CO)_5$ (M=Cr, W) is assessed: cis-HW$(CO)_4P(OMe)_3^-$, $HW(CO)_5^-$ > $HCr(CO)_5^-$-$Br^-$ > trans-HFe$(CO)_3P(OMe)_3^-$ > $Mn(CO)_5^-$ > $HFe(CO)_4^-$ > PP$h_3$