• Proceedings of the Membrane Society of Korea Conference
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• 2001.05a
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• pp.13-20
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• 2001

• Journal of the Korea Institute of Building Construction
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• v.18 no.5
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• pp.403-412
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• 2018

Recently, needs for utilization of recycled aggregate have been increasing. However, its utilization has been limited due to its high alkalinity, which mostly came from the unremoved cement paste particles that were attached at the surface of recycled aggregate. Various efforts has been made to reduce its alkalinity by using $CO_2$, but currently available methods that uses $CO_2$ generate the problem with pH recovery. Considering the fact that supercritical $CO_2$ ($scCO_2$) can provide more rapid carbonation of cement paste than by normal $CO_2$, $scCO_2$ was utilized in this work. The reaction between $scCO_2$ and hydrated cement paste has been systematically evaluated. According to the results, it was found that powder type showed higher carbonation compared to that of cube specimens. It seems the carbonation by $scCO_2$ has occurred only at the surface of the specimen, and therefore still showed some amount of $Ca(OH)_2$ calcium aluminates after reaction with $scCO_2$. With powder type specimen, all $Ca(OH)_2$ was converted into $CaCO_3$. Moreover, additional calcium that came from both calcium aluminate hydrates and calcium silicate hydrates reacted with $scCO_2$ to form $CaCO_3$. After carbonation with $scCO_2$, the powder type specimen did not show pH recovery, but cube specimens did show due to the presence of portlandite.

• Journal of Microbiology and Biotechnology
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• v.11 no.5
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• pp.772-775
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• 2001

A highly $CO_2$ tolerant microalga, Chlorella KR-1, has been isolated and used to fix $CO_2$ from actual flue gas. Growth of Chlorella KR-1 with the supply of flue gas from a liquified natural gas boiler was comparable to that obtained with 10% $CO_2$. Chlorella KR-1 produced from $CO_2$ fixation using the flue has about 50% crude protein with balanced amino acid profiles. Toxicity was not detected when the microalga was used as a feedstuff for chicks. These results indicate that the KR-1 cells could be a favorable protein source for poultry.

• Transactions of the Korean hydrogen and new energy society
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• v.6 no.2
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• pp.53-63
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• 1995

A 100kW class stack consisting of 10 molten carbonate fuel cells has been fabricated. Internally manifold stack has been tested for endurance. Each cell in the stack had an electrode area of $100cm^2$ and reactant gases were distributed in each cells in a cross-flow configuration. Initial and long term operation performance of the stack was investgated as a function of gas utilization using a specially designed small scale stack test facility. It was possible to have a stack with an output of more than 100W using an anode gas of 72% $H_2/18%$ $CO_2/10%H_2O$ and cathode gas of 33% $O_2/67%$ $CO_2$ and 70% Air 30% $CO_2$. The output and voltage of the stack at a current 15A($150mA/cm^2$) and gas utilization of 0.4 showed 125.8W and 8.39V respectively by elapsed time of 310 hours operation. In long term operation characteristics, the voltage drop of 52.4mV/1000hour was observed after more than 1,840 hours operation. Among the voltage drop, the OCV loss was highest than other voltage loss such as internal resistance and electrode polarization. Non uniformity of 2voltages and degradation of cell voltage in the stack was observed in according to changing the utilization rate after a long term operation. Further work for increasing the performance prolonging the life of the stack are required.

• Journal of the Korean Applied Science and Technology
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• v.4 no.2
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• pp.1-6
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• 1987

• Journal of Korean Library and Information Science Society
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• v.55 no.2
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• pp.243-266
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• 2024

In foreign countries, ISNI-based creative work identification and linkage services have been established and operated in various fields, while in Korea, ISNI utilization and linkage services limited to some fields are operated mainly by the National Library of Korea. The purpose of this study is to propose an ISNI-based linkage and utilization service that can be applied in Korea. To achieve the purpose of this study, we examined overseas ISNI linkage cases and identified the requirements of related organizations. We also proposed four ways to build ISNI sharing and convergence services. These include establishing Identifiers Co-operation Initiatives (ICI), establishing creator profiles, activating ISNI through the publishing industry, and activating ISNI services through external linkages. We hope that this study will serve as a basis for building ISNI-based linkage and utilization services.

• Journal of Ecology and Environment
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• v.29 no.6
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• pp.551-558
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• 2006

Effects of Pb and $CO_2$ on soil microbial community associated with Pinus densiflora were investigated using community level physiological profiles (CLPP) and 16S rDNA PCR-denaturing gradient gel electrophoresis (DGGE) methods. Two-years pine trees were planted in Pb-contaminated soils and uncontaminated soils, and cultivated for 3 months in the growth chamber where $CO_2$ concentration was controlled at 380 or 760 ppmv. The structure of microbial community was analyzed in 6 kinds of soil samples (CA-0M : $CO_2$ 380 ppmv + Pb 0 mg/kg + initial, CB-0M : $CO_2$ 380 ppmv + Pb 500 mg/kg + initial, CA-3M : $CO_2$ 380 ppmv + Pb 0 mg/kg + after 3 months, CB-3M : $CO_2$ 380 ppmv + Pb 500 mglkg + after 3 months, EA-3M : $CO_2$ 760 ppmv + Pb 0 mg/kg + after 3 months, EB-3M : $CO_2$ 760 ppmv + Pb 500 mg/kg + after 3 months). After 3 months, the substrate utilization in the uncontaminated soil samples (CA-3M vs EA-3M) was not significantly influenced by $CO_2$ concentrations. However, the substrate utilization in the Pb-contaminated soil samples (CB-3M vs EB-3M) was enhanced by the elevated $CO_2$ concentrations. The results of principal component analysis based on substrate utilization activities showed that the structure of microbial community structure in each soil sample was grouped by Pb-contamination. The similarities of DGGE fingerprints were 56.3 % between the uncontaminated soil samples (CA-3M vs EA-3M), and 71.4% between the Pb-contaminated soil samples (CB-3M vs. EB-3M). The similarities between the soil samples under $CO_2$ 380 ppmv (CA-3M vs CB-3M) and $CO_2$, 760 ppmv (EA-3M vs EB-3M) were 53.3% and 35.8%, respectively. These results suggested that the structure of microbial community associated with Pinus densiflora were sensitively specialized by Pb-contamination rather than $CO_2$ concentration.

• 연구논문집
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• s.31
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• pp.45-51
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• 2001

One of emerging technologies under development in the advanced countries is considered as RDF(Refuse Derived Fuel) power generation, which could meet both the requirement of an alternative energy resource utilization and $CO_2$ reduction. This paper deals with the effect to the thermal effiency and CO2 reduction of RDF firing power generation. The statistical data of domestic MSW generation in last year in small and medium cities for evaluating the merits of the RDF power generation were used. The analysis for RDF power generation compared to the existing incinerator w/o(or w/) power generation shows around 20.6%(10.0%) up in the total thermal efficiency and 57.0%(31.4%) up in the $CO_2$ reduction respectively.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.118-119
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• 2016

γ-C₂S is known as a kind of substance that it does not react with water at room temperature. However it could react with the CO₂ producing CaCO₃ and silica gel as the carbonation products. Thus γ-C₂S can be used as a mineral addition to improve the compressive strength and durability of concrete. On the other hand, the manufacture of γ-C₂S can give an effective utilization of industrial by-product with low energy consumption and low CO₂ emission. This paper aims to summarize the development situation on this field.

• Asian-Australasian Journal of Animal Sciences
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• v.5 no.3
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• pp.511-517
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• 1992

Ethanol was utilized by mixed rumen microbes, but addition of pentachlorophenol (25 mg/l), a methanogen inhibitor, suppressed the utilization of ethanol. Carbon monoxide (50% of the gas phase), a hydrogenase inhibitor, more strongly suppressed the utilization of ethanol, propanol, and butanol. These results suggest that the major ethanol utilizers are $H_2$ producers. Ethanol utilization was depressed at low pH (below 6.0). Since methanogens were shown to be relatively resistant to low pH, it appears that ethanol utilizers are particularly sensitive to low pH. Ruminococcus albus and R. flavefaciens in mono-culture produced ethanol from carbohydrate (glucose and cellobiose), even when a high level (170 mM) of ethanol was present. Ethanol was not utilized even in the absence of carbohydrate, but the co-culture of these bacteria with methanogens resulted in the utilization of ethanol, i.e., when $H_2$ was rapidly converted to $CH_4$, R. albus and R. flavefaciens utilized ethanol. These results suggest that ethanol is utilized when the electrons liberated by the oxidation of ethanol are rapidly removed, and ready electron disposal in ethanol-utilizing, $H_2$-producing bacteria is accomplished by the interspecies transfer of $H_2$.