• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1997.05a
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• pp.59-61
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• 1997

무토양재배시스템은 가급적 경량화이면서 집약적인 형태를 가지며, 환경보존차원을 위하여 밀폐형 순환식 재배시스템이 중시되고 있다. 무토양재배시스템은 DFT에서 NFT나 고형배지로 갈수록 외기의 환경변화에 대하여 비교적 근권부근의 환경변화가 크기 때문에 노출되어 있는 뿌리에 영향을 미치는 것으로 사료된다. (중략)

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 1997.05a
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• pp.62-64
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• 1997

작물생육은 근권 부근의 온도와 밀접한 관계가 있다. 따라서 외부환경의 영향을 받기 쉬운 단순 경량화된 순환형 무토양재배시스템내의 양액 또는 배지의 온도 변화를 파악하여 환경조절을 통한 적정 생육환경을 조성할 수 있다면, 작물의 생산성에 기여할 수 있다. 본 연구는 순환식 무토양재배시스템의 위치별 온도 분포 및 배양액의 공급 과 온도변화와의 관계를 분석하였다.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2023.04a
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• pp.48-49
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• 2023

• Korean Journal of Medicinal Crop Science
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• v.8 no.2
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• pp.123-128
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• 2000

This study was carried out to determine factors affecting on the mass propagation of Rehmannia glutinosa seedlings in bioreactor culture. Air-lift type bioreactor was more compatible to shoot formation than stirrer type. Fifty grams(90 stem explants) of inoculum in 1.5L medium was placed into 2.5L bioreactor with aeration rate of 0.5 v.v.m., which was proper for effective shoot formation. Adding MES as pH buffer to culture medium increased the numbers of shoot formation. Adding 5g/l of anti-vitrifying agent into culture medium was highly effective for diminishing the rate of vitrification in shoots formed.

• Korean Journal of Microbiology
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• v.42 no.4
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• pp.257-264
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• 2006

Fifty eight Cryptococcus neoformans strains isolated from clinical and environmental sources in Korea were examined for their serotypes and extracellular enzyme activities. Among the 51 strains isolated from clinical sources, 48 strains were serotype A (94.1%), 2 strains were serotype B (3.92%), and 1 strain was serotype D (1.96%). All seven environmental strains isolated from pigeon excreta were identified as serotype A. All isolates of C. neoformtans were positive for the production of extracellular proteinase and phospholipase. In the API-ZYM system, all fifty eight isolates produced alkaine phosphatase, esterase C4, esterase lipase: C8, leucine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrase, $\alpha$-glucosidase and $\beta$-glucosidase. Thirty nine isolates (67.2%) of C. neoformans produced N-acetyl-$\beta$-glucosidase. Two isolates, serotype B, and B only one serotype A produced $\beta$-glucuronidase. Analysis of enzymatic profiles to 21 enzymes revealed four biotypic patterns among the 58 strains. The enzymatic patterns of C. neoformans isolated from clinical and environmental sources represented a significant relationship with the serotypes.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.11 no.1
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• pp.189-196
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• 1991

The objective of this study was to investigate the effect of temperature on microbial characteristics and treatment efficiency in aerated submerged biofilm process. From the results of the research, conclusions were derived as following: 1. Biofilm density, attached biomass and biofilm thickness were $30-42mg/cm^3$, $1.2-2.7mg/cm^2$ and $380-690{\mu}m$, respectively. These were greatly affected by the variation of temperature ($5-20^{\circ}C$) and packing ratio(45-90%). 2. The ratio of suspended biomass to the total biomass in the reactor was in the range of 10 to 50 % in accordance with the variation of temperature and packing ratio. Therefore, the portion of suspended biomass cannot be neglected. 3. BOD removal efficiency increased as either temperature or biomass(suspended and attached) concentration increased. 4. The aerated submerged biofilm process appeared to be less affected by temperature variation and the estimated temperature correction coefficient of the Van't Hoff-Arrhenenius equation was 1.042.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.9
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• pp.997-1002
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• 2007

The objectives of this research are to remove dissolved organic matter and nitrogen compounds by using aerated submerged bio-film(ASBF) reactors in batch systems and improve understanding of dissolved organic matter and nitrogen compounds removal rates with dynamic relationships between heterotrophic and autotrophic bacteria in the fixed-film reactor. This research explores the possibility of enhancing the performance of shallow wastewater treatment lagoons through the addition of specially designed structures. These structures are designed to encourage the growth of a nitrifying bacterial bio-film on a submerged surface. Specially, the effects of cold temperatures on the dissolved organic matter and ammonia nitrogen performance of the ASBF pilot plant was investigated for the batch system. It is anticipated thai the ASBF would be used for a design of biological treatment for removing of dissolved organic matter and nitrogen compounds in new wastewater treatment plants as well as existing wastewater treatment plants.

• Korean Journal of Environmental Biology
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• v.33 no.4
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• pp.403-411
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• 2015

To understand differences of environmental factors and planktonic communities in closed (CS) versus open (OS) enclosed experimental systems, we performed a study on a 100-L indoor-type artificial marine microcosm. For environmental factors, including water temperature, dissolved inorganic phosphorus, and dissolved silica, there were no significant differences between CS and OS; however, salinity was higher in CS than that of OS due to the evaporation effect. The concentration of dissolved oxygen and dissolved inorganic nitrogen was lower in CS than in OS. The abundance of phytoplankton was lower in CS than in OS. However, abundance of autotrophic nanoflagellates and heterotrophic bacteria varied inversely with that of phytoplankton abundances. In particular, the abundance of heterotrophic nanoflagellates and ciliates increased with bacterial growth after a time lag. Therefore, environmental factors and planktonic communities in CS gradually changed over time and characterized a different artificial ecosystem than in OS.

• Applied Biological Chemistry
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• v.35 no.6
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• pp.470-474
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• 1992

For the further development of thelepin analog as antibiotic agents, we undertook the synthesis of spirobenzopyranone derivative ${\underline{5}}$ as thelepin analog by oxidative phenol coupling. The spirobenzopyranone analog ${\underline{5}}$ showed high activity against Bacillus subtilis (IFO 3108) in $5\;{\mu}g/disc$.

• Journal of Environmental Health Sciences
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• v.9 no.1
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• pp.63-76
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• 1983

중금속은 해수에서보다 해수중의 생물계에 그 농도가 더 높은 것으로 알려져 있으며 수은도 무기형으로 생물계에 존재하다가 생물활동으로 인해 알킬형으로 변한다. food chain이 미량금속 축적의 주통로로 알려져 있으나 그외 몇가지 방법이 제시되고 잇다. 특히 연체동물은 미량금속의 축적현상이 온도, 폭로시간, 시간, 생리적 활동에 다라 상당히 달라진다. 또한 유기알킬 수은이 무기수은보다 비교적 낮은 독성을 나타내지만 후자의 피해도 무시할 수는 없다. 굴(crassostrea virginica)은 염화수은농도가 비교적 낮은 상태에서도 상\ulcorner량의 축적현상을 보여주었다. 두개의 compartment system을 연계적인 상태에서 보면 첫 compartment에서의 초기축적은 가역적이었으나 둘째 Compartment에서 측정된 원실율로 보아 비가역적 축적이상을 확인해 주었다. 뿐만 아니라 미량금속이 아가미와 외부 근육에서 가장 높은 축적률을 보인것은 flow system의 regression moder과 매우 흡사함을 암시하며 농도가 낮은 상태에서의 축적이상에 중요한 의미를 부여하였다.