• Korean Journal of Microbiology
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• v.35 no.2
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• pp.153-157
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• 1999

The effececl of levanoclaose produced by levanase Croni Pseuc/olol~~o!!n.s sp. K-52 on pnnciple inlesimal microflorawas investigated. The reaction product, levanoctaose, was used as a carbon source for various intestinalmicroflora. Especially. Bijidobacteriulolr~ adolescentis and Lnctohaciilrrs ocidophilus grew effectively in vitroexpeiiments, whereas Clostridiunz per.frilol~gerzs, Bactetvid,~ngilis, Eschericlzin. coli, and Stnplzylococcus nureirsdid not. Therefore, levanoctdose seemed to proinole selectively the growth ol" B. ndo1escenti.r and L. acidol~hi-/us. In Lhe in viva experiments, the effects of levanoctaose on inlestinal nucroflora were examined on heirgrowth. $\beta$-fri~ctosidase acliviiy. and butyrate concenuation in rats. Appuently, die number of fecal Bifidobacteria.the amount of bulyrate, and $\beta$-hctosidase activity were increased, whereas total aerobes 'and pH werereduced in rals Eed leviu~octaose diets, cornpxed with hose of the control diets. We concluded hat those effecismay be beneficial in improving gastrointestinal health.astrointestinal health.

• KSBB Journal
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• v.17 no.1
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• pp.73-79
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• 2002

The method to optimize the microbial production of ethanol from CO using Clostridium ljungdahlii was developed. The kinetic parameter study on CO conversion with Clostridium ljungdahlii was carried out and maximum CO conversion rate of 37.14 mmol/L-hr-O.D. and $K_{m}$ / of 0.9516 atm were obtained. It was observed that method of two stage fermentation, which consists of cell growth stage and ethanol production stage, was effective to produce ethanol. When pH was shifted from 5.5 to 4.5 and ammonium solution was supplied to culture media as nitrogen source at ethanol production stage, the concentration of ethanol produced was increased 20 times higher than that without shift. Ethanol production from CO in a fermenter with Clostridium ljungdahlii was optimized and the concentration of ethanol produced was 45 g/L and maximun ethanol productivity was 0.75 g ethanol/L-hr.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.8 no.3
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• pp.317-326
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• 2003

In order to improve our knowledge of the characteristics of organic compounds in coastal waters, water samples were collected from the Incheon coastal region, the Hyungsan River in Youngil Bay and the Busan coastal region. Also, mooring was carried out near the Kanghwa Island and Seo Island. In this study, the relationship between the total organic carbon (TOC) and salinity, chemical oxygen demand (COD) and salinity were evaluated and determined. Riverine end-member of TOC into the Korean coastal area and its COD estimated from these relationships were 5.32 mg C/l and 8.87 mg O$_2$/l, respectively. The oxidation efficiency of COD to TOC estimated using the high-temperature catalytic oxidation method was about 47％. The linear relationship between TOC and COD was derived as COD (mg O$_2$/l)=0.61${\times}$TOC (mg C/l) -0.03, (R$^2$=0.66). Therefore, it is possible to estimate total organic carbon using this equation from previously reported chemical oxygen demand.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.2
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• pp.145-166
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• 2021

For several decades, sediment traps have served as one of the key tools for constraining the biological carbon pump (BCP), a process that vertically exports particulate organic carbon (POC) and associated biogenic materials from marine primary production in surface waters to the deep ocean interior. In this paper, I introduced the general methods, the current status of global sediment trap studies, and importance of it to understand the deep ocean carbon cycling. Recent studies suggest that sinking POC in the deep ocean are more complex and spatio-temporally heterogeneous than we considered. Especially researches those studied resuspended and laterally transported particles are presented. Researches that used organic (radiocarbon; ¹⁴C) and inorganic (Al) tracers to understand the oceanic POC cycling and the significance of resuspended particles are reviewed, and the importance of radiocarbon study by using MICADAS (Mini radioCarbon Dating Systems) is emphasized.

• Journal of the Korean Vacuum Society
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• v.21 no.2
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• pp.113-119
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• 2012

Carbon nanotubes have emerged as a promising material for multifaceted applications, such as composited nanofiber, field effect transistors, field emitters, gas sensors due to their extraordinary electrical and physical properties. In particular, synthesis of vertically aligned carbon nanotubes with a high aspect ratio has recently attracted attention for many applications. However, mass production of high-quality single-walled carbon nanotubes is still remain elusive. In this study, an effect of chemical vapor deposition conditions, including catalyst thickness, feedstock flow rate, and growth temperature, on synthesis of carbon nanotube was systematically investigated.

• Korean Journal of Microbiology
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• v.36 no.2
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• pp.97-102
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• 2000

In order to use Metarhizizmn~ anisopliae as a biological pesticide, effect of envrionmental factors on nlycelial growth, spore formation, and extracellular enzyme activity in culture broth of M. anisopliae DGUM 35001 was determined. Optimal temperature was 26^{\circ}C.$ and optimal pH ranged from 5 to 9. Among the complex media tested, MCM and SDPY media were the most favorable for mycelial growth. When Czapek-Dox agar was used as a mnimal medium, glucose and sucrose among the saccharides were very excellent source of carbohydrate. Among the biopolyners tested. chitin was the most favorable source for mycelial growth and produced high aerial inycelia. Urea and ammonium phosphate as an inorganic nitrogen source and bacto-peptone and soytone as an organic nitrogen source enhanced the mycelial growth When serine as a source of amino acid was supplemented, excellent mycelial growth was shown. Large amount of spores could be obtained from the aerial mycelia of starch medium. When the culture broth was filtrated and then the concentrate with ammonium sulfate was used as a crnde enzyme solution, high enzyme activities of amylase and protease were shown. However, lipase and chitinase activities were comparatively low.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.225-230
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• 1996

탄화규소(SiC)가 도포된 핵연료 제조를 위해 고온 연소 합성법(Self-propagating High Temperature Synthesis, SHS)이 적용되었으며, 반응물로 규소(Si) 분말, 규소 박막 (Si-thin film), 흑연 분말과 카본(C) 화이버가 사용되었다. 규소 박막은 프라즈마가 강화된 화학증착법(a microwave pulsed electron cyclotron resonance plasma enhanced chemical vapor deposition)으로 준비되었다. 그 결과 규소와 탄소의 고온 연소 합성반응 생성물은 반응물이 분말이거나 박막에 관계없이. 탄화규소(SiC)가 합성되었으며, 생성물의 형상(morphology)은 초기 탄소의 형상에 의존하였다. 본 연구를 통해 고온 연소 합성법이 탄화규소와 탄소가 도포된 핵연료 제조에 적용 가능함을 알 수 있었다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.1
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• pp.55-61
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• 2000

The electrochemical properties of hard carbon anodes in lithium ion batteries were improved by carbon coating using polyvinyl chloride (PVC). The reduction in irreversible capacity occured and the reversible capacity increased. It is suggested that the PVC carbon coating modifies the surface of hard carbon and reduces the surface reaction with species from air. The degree of the graphitization of PVC carbon was controlled by an addition of Ni, and the effect of the amount of Ni addition on the electrochemical properties was discussed.

• Microbiology and Biotechnology Letters
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• v.26 no.4
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• pp.303-308
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• 1998

A bacterial strain which utilizes phenol under denitrifying condition was isolated from the industrial waste water collected from the Chong-ju Industrial Complex. The strain was identified as Pseudomonas species from the morphological, physiological, and biochemical characteristics and designated as HL100. The strain can utilize phenol as the sole source of carbon and energy when nitrate is provided as the terminal electron acceptor. The isolated strain completely degraded 3 mM of phenol within 110 hour with concomitant reduction of nitrate to nitrite. The observed maximum doubling time was 20 hours. Under appropriate condition, complete reduction of nitrate to atmospheric N$_2$ was observed indicating that the isolated strain could perform complete steps of denitrification. The strain showed optimal growth at pH 7.0 and temperature of 37$^{\circ}C$ under denitrifying phenol-degrading condition. The strain can also utilize toluene as the sole carbon and energy source under the same growth condition. However, no growth was detected on xylene and benzene.

• KSBB Journal
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• v.19 no.1
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• pp.78-82
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• 2004

Experiments were carried out to select an organic nitrogen source and optimize the culture conditions for the production of arachidonic acid by Mortierella alpina DSA-12. Corn steep powder(CSP) was selected as an organic nitrogen source based on arachidonic acid production and raw material price. The optimum C/N ratio was in the range of 15 to 17 with the medium containing glucose as carbon source and CSP as nitrogen source. The optimum culture conditions for arachidonic acid production showed 500 rpm agitation and 25$^{\circ}C$ culture temperature at 0.5 vvm aeration. Under the optimum conditions, the concentration of cell, total lipid and arachidonic acid were 21.8 g/L, 10.2 g/L and 3.70 g/L, respectively, from 50 g/L glucose and 18 g/L CSP. In the 500 L fermenter with 0.5 vvm aeration and 200 rpm agitation, the concentration of cell, total lipid and arachidonic acid were 19.8 g/L, 9.1 g/L and 3.67 g/L, respectively, from 50 g/L glucose and 18 g/L CSP. This result showed that an arachidonic acid production could be possible with a bench-scale fermenter using corn steep powder as a nitrogen source.