• Journal of Hydrogen and New Energy
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• v.20 no.2
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• pp.168-178
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• 2009

To check feasibility of SEWGS(Sorption Enhanced Water Gas Shift) system, conceptual design and sensitivity analysis of operating variables have been investigated based on a design program of two-interconnected fluidized bed. Based on the conceptual design results, the optimum configuration for SEWGS was considered. Among three configurations, bubbling beds system was selected as the best configuration. Process design results indicate that the SEWGS system is compact and feasible. Based on the selected operating conditions, the effects of variables such as pressure, $CO_2$ capture capacity, solid inventory, CO conversion and $CO_2$ capture efficiency have been investigated as well.

• Broadcasting and Media Magazine
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• v.11 no.1
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• pp.78-85
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• 2006

Cognitive radio is a paradigm for wireless communication in which either network of wireless node itself changes particular transmission or reception parameters to execute its tasks efficiently without interfering with the licensed users. This paper represents a performance of the cognitive radio technology on dual polarized MIMO system using six-port receiver. Six-port technology is well known direct conversion receiver. In this paper, a six-port phase discriminator based polarization signal separation is shown. That is, the SER(Symbol Error Rate) performance is improved using polarization separator and simple receiver architecture is proposed applying six-port receiver. The six-port technology has priority to adapt changeable frequency system and variable environments for cognitive radio. In general, dual polarized MIMO system has good capacity and quality using polarization separator [1].

• Bulletin of the Korean Chemical Society
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• v.35 no.4
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• pp.1177-1181
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• 2014

A 2D grid-like (4, 4)-connected topology coordination polymer, $[Co(BTA)_2(H_2O)_2]_n$ (1), where HBTA = 2-(1H-benzotriazol-1-yl)acetic acid, has been synthesized by hydrothermal method and characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis and surface photovoltage spectroscopy (SPS). X-ray diffraction analyses indicated that 1 displays octahedral metal centers with secondary building units (SBUs) [$Co(BTA)_2(H_2O)_2$] bridged by the $BTA^-$ ligands. In the crystal, the 2D supramolecular architecture is further supported by $O-H{\cdots}O$, $O-H{\cdots}N$, $C-H{\cdots}O$ hydrogen bonds and ${\pi}{\cdots}{\pi}$ stacking interactions. The SPS of polymer 1 indicates that there are positive response bands in the range of 300-600 nm showing photo-electric conversion properties. There are good relationships between SPS and UV-Vis spectra.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.343-345
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• 2001

새로운 대체 에너지원으로 주목받고 있는 풍력 에너지의 효율적인 이용을 위하여 기개발되어 운용중인 30kW급 수직-수평축 통합형 풍력발전시스템을 대상으로 낙도 지역 등에서 사용할 수 있는 독립형 전원장치를 설계하였다. 설계된 시스템은 무보수 밀패형 배터리와 자체 개발한 배터리 충전 제어 장치 및 교류 전원 출력용 인버터로 구성되며 장시간 바람이 불지 않는 경우에도 양질의 전원을 연속적으로 부하에 공급할 수 있도록 설계되었다.

• Journal of Hydrogen and New Energy
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• v.30 no.1
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• pp.35-42
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• 2019

Recently, the gradual increase in energy acceptance is mostly satisfied by fossil fuels, but research and development of renewable energy sources are attracting attention due to fossil fuel supply and greenhouse gas problem. The disadvantage is that renewable energy can not be produced continuously. This being so, energy storage is an important technology in renewable energy. In this study, microwave was used to convert carbon receptor-carbon dioxide to gas fuel.

• Asian-Australasian Journal of Animal Sciences
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• v.4 no.3
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• pp.285-291
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• 1991

Two experiments were conducted to evaluate the effect of mold inhibitor in the ration which had two different protein levels (18% and 12%) and two different particle sizes (80 or 40% of the particles in the ration less than 1.19 mm). The experimental diets with ave. 12.7% moisture which were treated at the level of 0.1% mold inhibitor were stored under 85% humidity and at $29{\pm}1^{\circ}C$ for 10 to 40 days. In experiment 1, after 40 days of storage the $CO_2$ production in the feed treated with mold inhibitor was higher (p < 0.01) than when 40% of the ration's panicle size was 1.19 mm. Aflatoxin production in the experimental diet with mold inhibitor was affected (p<0.05) by the levels of protein and the different particle size ranges after 40 days storage. The interaction of protein levels and particle size ranges on the anatoxin and $CO_2$ production was significant (p<0.05) at 40 days storage. In experiment 2, there was a decrease in total body weight gain and total feed intake observed in chicks fed the untreated diet of 18% protein with 40% of the particles in the ration less than 1.19 mm stored for 40 days. Feed conversion was depressed (p<0.05) in the chicks fed the untreated diets of both particle sizes. Particle size X types of feed interaction in feed conversion was significant (p<0.05).

• Journal of Institute of Convergence Technology
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• v.10 no.1
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• pp.19-24
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• 2020

The purpose of the study is to investigate the thermal durability characteristics of the Pt catalyst and additives used in a catalytic combustor. The catalyst used in the experiment was based on Pt (3 wt%), and a total of 12 types were prepared using a combination of additives (Ni, La, Ce, Fe, and Co). From the results, In the fresh state, the two types of combination catalysts with the highest C₃H₈ conversion were Pt_Ce (79.9%) at 500℃, and in the three types of combination catalysts, Pt_La_Ni (93.4%) at 500℃ had the best performance. Among aged catalysts at 850℃ and 8 hours, Pt-La-Ni and Pt-Ni-Ce catalysts showed the highest C₃H₈ conversion of about 71% at 500℃.

• Journal of the Korean Chemical Society
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• v.23 no.6
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• pp.402-411
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• 1979

The synthesis of pyrrolidone-N-sulfonyl chloride has been carried out by the reaction of pyrrolidone with sulfuryl chloride in benzene. It was attempted to study the catalytic effect of pyrroldone-N-sulfonyl chloride as an initiator for anionic polymerization of pyrrolidone. It was found that as a concentration of initiator decreased, inherent viscosity of the resulting polymer increased up to 1.8 dl/g. The highest rate of polymerization and equilibrium conversion was observed when mole ratio of PNSC to KOH was 0.25. In general, the observed value of polymerization and equilibrium conversion in circumstances using PNSC/KOH catalysis system were higher than using $CO_2$/KOH catalysis system.

• Journal of the Korean Solar Energy Society
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• v.21 no.4
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• pp.29-35
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• 2001

The chemical heat storage as the one way of utilization for high temperature solar energy was considered. The stram reforming reaction of methane was chosen for endothermic reaction. The reactor was made of stainless steel tube and it's dimension was 0.635 cm I.D. and 30 cm long, coiled tube because of the geometry requirement of solar receiver The effects of space velocity and reactants mole ratio on the methane conversion and CO selectivity were examined. From the experimental results, the optimum steam/methane mole ratio was determined.

• Journal of the Korean Applied Science and Technology
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• v.27 no.1
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• pp.29-36
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• 2010

The effects of La addition to Ni/$CeO_2$ methane partial oxidation catalysts were investigated. Catalysts were prepared by the impregnation and urea methods. In the preparation of catalysts, La content was changed from 1 wt% to 3wt%. Catalysts that contain 2wt% La showed the highest methane conversion of about 80% and CO selectivity of 84% and $H_2$ selectivity of 70%. This result may be stemmed from that, when La content is 2wt%, a fluorite oxide-type structure is well formed and carbon deposition is also decreased. Among the catalysts, 2.5wt% Ni/Ce(La)Ox showed the highest catalytic activity. From the experiment of changing reaction temperature with 2.5wt% Ni/Ce(La)Ox catalyst, it was found that the optimum reaction temperature is $750^{\circ}C$ and at this temperature methane conversion was about 90%, CO and $H_2$ selectivities were 94 and 80%, respectively.