• KSBB Journal
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• v.13 no.5
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• pp.626-630
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• 1998

Ammonium limitation did not promote ply(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) production of Azotobacter vinelandii UWD. In acid phase, ammonium limitation during utilization of propionic acid and butyric acid led to 35% decrease in product yield. In glucose phase, both biomass yield and polymer yield decreased about 22% under ammonium limitation. However, in nitrogen-fixing culture glucose was consumed 25% faster and the final PHBV wt% decreased slightly. Under nitrogen limitation a portion of the carbon sources was used fro nitrogen fixation rather than biomass and polymer formation, resulting in a decrease in biomass yield and polymer yield.

• Journal of Environmental Science International
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• v.2 no.4
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• pp.357-365
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• 1993

This study was conducted for the efficient utilization of biomaterials such as starch residue, tangerine skin, and green tea residue, which are agricultral by-products discarded in Cheju Province annually, as adsorbents and biomaterials were examined for their removal ability of heavy metal ions in waste water by batch adsorption experiments. The removal efficiency of biomaterials for heavy metal ions was above 80-90% and almost similar to activated carbon and the adsorption ability of those treated with 포르말린 was improved in the green tea residue only for $Pb^{2+}$, $Cu^{2+}$, and $Zn^{2+}$. In the conditions of pH, the removal efficiency of heavy metal ions was high in the range of 5-7. In the solutions which heavy metal ions were mixed, the removal efficiency was similar at $Ag^+$, $Pb^{+2}$ and reduced to about 10% at the other ions, as compared with the solutions they were not mixed. Adsorption isotherm of biomaterials was generally obeyed to Freundlich formular than Langmuir formular and Freundlich constant, 1/n were obtained in the range of 0.1-0.5.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.209-210
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• 2012

Cement is an essential material for social infrastructure. Cement production process for cement itself is energy-intensive and requires a large amount of natural resources for fuel and raw materials. This study is to development of recycled cement from waste concrete powder in manufacturing process of recycled aggregate concrete. Recycled cement is low carbon and green growth materials concept for eco friendly construction environment. From the test results, waste concrete powder is same chemical proportion regardless of manufacturing process of recycled aggregate concrete.

• Journal of Energy Engineering
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• v.8 no.1
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• pp.137-142
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• 1999

지구 온난화 현상의 주된 원인인 CO2 가스의 분해를 위해, 스트론튬 페라이트를 이용한 CO2 가스 분해 반응에 대해 연구하였다. CO2 가스 분해를 위한 반응 매체로 스피넬형 조성과 마그네토프롬바이트형 조성의 스트론튬 페라이트 미세분말을 공침법으로 제조한 후, H2 가스로 환원시켜 산소부족형 스트론튬 페라이트 분말을 제조하였다. 이 산소부족형 스트론튬 페라이트 분말은 CO2 가스를 환원, 분해시키면서 산화된다. 이러한 원리를 이용한 CO2 분해 반응에서 스피넬형 조성 스트론튬 페라이트 분말이 마그네토프롬바이트형 조성 분말 보다 빠르게 많은 양의 CO2 가스를 분해 시켰다. 페라이트 중의 스트론튬이 산화·환원 반응을 촉진시키는 것을 관찰할 수 있었다.

• Korean Journal of Microbiology
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• v.29 no.2
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• pp.143-147
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• 1991

The root nodules and Glycine max were classified as determinate nodule based on their morphological characteristics, and isolated endosymbiont as a Bradyrhizobium based on its growth rate and single subpolar flagellum. The isolate was similar to B. japonicum USDA110 in utilization of carbon source, growth at 38.deg.C and 2% NaCl, production of $H_{2}$S and especially in the restriction endonuclease digestion pattern of symbiotic genes, allowing them to be placed in sTI group together. The former, however, grew better than the later in broad pH range from 5.0 to 9.5. Infectivity and effectivity of the isolate were confirmed by inoculation of soybean seedlings with the isolates. Characteristics of the reisolated endosymbiont from induced root nodules were identical to those of the first isolate. From these results, it was confirmed that Bradyrhizobium strain isolated from the root nodules of Glycine max was a real symbiont, and was named B. japonicum SNU001.

• Journal of Microbiology and Biotechnology
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• v.18 no.6
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• pp.1005-1010
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• 2008

The genus Burkholderia consists of extremely versatile bacteria that occupy diverse niches and are commonly encountered in the rhizosphere of crop plants. In this study, we characterized three plant growth promoting strains assigned as Burkholderia sp. using biochemical and molecular characterization. The Burkholderia spp. strains CBMB40, CBPB-HIM, and CBPB-HOD were characterized using biochemical tests, BIOLOG carbon substrate utilization, fatty acid methyl ester analysis, analysis of recA gene sequences, and DNA-DNA hybridization. The results from these studies indicated that the strains CBMB40, CBPB-HIM, and CBPB-HOD can be assigned under Burkholderia vietnamiensis, Burkholderia ubonensis, and Burkholderia pyrrocinia, respectively.

• Microbiology and Biotechnology Letters
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• v.10 no.4
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• pp.237-243
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• 1982

A microorganism, YS-40 strain which powerfully produced penicillinase was isolated from soil. The morphological and cultural characteristics of the strain ; spore chain, spore surface, aerial mass color, melanoid pigment, reverse side pigment, other soluble pigment, and physiological properties were investigated. As the results of various examinations, the strain YS-40 was identified to be similar to Streptemyces bobili except the spore chain and the utilization of L-rhamnose among the various carbon sources.

• Journal of Microbiology and Biotechnology
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• v.2 no.4
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• pp.273-277
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• 1992

Treatment of poultry feces with Tolura sp. CH-30 produced a material that was significantly deodorized and showed a promotive effect on plant growth. Tolura sp. CH-30 grew on the poultry feces, deodorizing the feces by assimilation of volatile fatty acids, which are the source of the offensive odor, as a carbon source. Significant degradation of uric acid also occurred. In the treatment of feces with Tolura sp. CH-30, it was possible to deodorize feces in a short time, but reduction in the amount of urate-N was not enough. Urate-N inhibited plant growth due to an excessive nitrogen content produced as a result of rapid decomposition. Therefore, we propose a recycle-treatment plan using poultry feces treated with Tolura sp. CH-30. After the recycle-treatment, the amount of urate-N contained in the recycle-treated poultry feces was small and the recycle-treated poultry feces showed a promotive effect on plant growth when it was added at a nitrogen content of 1.6 g/600 g soil/pot.

• Journal of Microbiology and Biotechnology
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• v.2 no.2
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• pp.115-121
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• 1992

In order to broaden the spectrum of substrate utilization of a Gram negative bacterium Zymomonas mobilis which has a great potential as an industrial ethanol producing microorganism, cloning of $\alpha$-amylase gene into Z. mobilis ZM4 was tried. The $\alpha$-amylase gene was isolated from Bacillus stearothermophilus. By Southern blot analysis, it was proven that the $\alpha$-amylase gene fragment was originated from a naturally occuring plasmid of B. stearothermophilus ATCC 31195. To place $\alpha$-amylase gene under the control of Z. mobilis promoter, two different Z. mobilis expression vectors, pZA26 and pLOI204, were used. The truncated $\alpha$-amylase gene was then introduced into these vectors. Both qualitative and quantitative activities of $\alpha$-amylase were observed in Z. mobilis cells harboring these plasmids with the $\alpha$-amylase gene inserted. Gas chromatographic analysis of ethanol showed that one of the Z. mobilis transconjugants was capable of producing 67 mM ethanol from rich medium(RM) containing 5% soluble starch as a sole carbon source.

• Journal of the Korean Operations Research and Management Science Society
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• v.18 no.1
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• pp.79-95
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• 1993

MARKAL (MARKet ALlocation) Model, one of the most sophisticated energy technology assessment model is applied to finding the optimum mix of energy sources and evaluating energy technology competitiveness in Korea. The model is capable of handling Multiple Objective Linear Programming to test the related cost minimization and environmental control function. In this paper three environmental regulation scenarios are observed including 10% and 20% reduction of carbon dioxide emission level. For the purpose of establishing the basic data base, Korea Reference Engergy System is also developed on the base of the year 1989 with technology utilization and energy flow analysis.