• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2009년도 학술발표회 초록집
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• pp.2132-2137
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• 2009

갈대(Phragmites communis Trin.)란 염분이 있는 곳에서 자라는 염생식물로서 우리나라 전역에 분포하고 있다. 지난 50년 동안 우리나라의 여러 습지에 걸쳐서 갈대는 우점종으로 자라왔고, 육지와 수중서식지에서 갈대의 확산범위는 증가하고 있다. 갈대의 확산은 다른 습지 식물의 서식지를 파괴하고, 갈대가 번식하면 동 식물들의 번식 자체가 어려울 뿐 아니라 갈대숲에 포식자가 늘어나 살아가기 어려운 환경으로 변하기때문에 갈대를 체계적으로 관리할 수 있는 방안이 마련되어야 한다. 본 연구는 우점종이 다른 두 습지에서 갈대군집의 성장률을 관찰하고, 토양의 화학적 분석과 식물의 생리적 분석을 통해 갈대군집 성장에 미치는 영양염류의 영향을 규명하였다. 연구 대상지는 한강하구에 위치한 장항습지와 성동습지로서 동일하게 갈대가 분포하며, 장항습지에는 줄 군락이 성동습지에는 새섬매자기 군락이 우점하고 있다. 분석 항목은 이화학적 항목을 비롯하여 용존유기탄소(DOC, dissolved organic carbon), 체외미생물효소활성도(Extracellular enzyme activities), 암모니아성 질소($NH_4^+$), 질산성 질소($NO_3^-$)을 분석하였다. 실험결과, 두 습지 갈대의 성장은 7월부터 9월에 증가하였고 성동습지의 토양성분이 점토질로 형성되어 높은 수분함량과 유기물함량을 유지하고 있기 때문에 갈대의 밀도가 높고 성장률이 활발한 것으로 나타났다. 또한 미생물활성과 환경인자간 양의 상관관계를 보아 환경인자들이 미생물 활성을 자극하고 미생물들은 식물의 성장을 촉진하여 영향을 주며, 반면 식물 뿌리는 enzyme을 생성하는 미생물에게 C 삼출물을 공급해 enzyme 활성에 영향을 미칠 것으로 사료된다.

• 분석과학
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• 제5권1호
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• pp.25-31
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• 1992

벤젠합성장치를 제작하여 액체섬광계수법을 이용한 방사성탄소 연대측정 시료인 목재, 목탄, 패류, 토양 등의 시료의 처리에 이용하였다. 이산화탄소, 아세틸렌의 생성 및 최종적으로 얻어지는 벤젠으로 이어지는 합성과정별 실험조건을 최적화하였다. 본 벤젠합성기를 이용함으로써 유기시료의 경우, 15시간의 합성을 통하여 탄산칼슘 기준으로 85% 이상의 합성수율을 얻을 수 있었다. 합성된 벤젠의 순도는 GC/MS 측정결과 99.9% 이상이었다.

• 한국농공학회논문집
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• 제53권6호
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• pp.121-128
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• 2011

Long-term water treatment performance analysis was conducted for the constructed wetland treating agricultural tailwater. Studied wetland was established in 2001 and operated from June, 2002 to November, 2010. Wetland vegetation cover was shown over 90 % coverage after 2005. According to vegetation development, accumulation of sediment nutrient was observed; Organic Carbon, T-P and T-N. In addition, DO concentration and temperature was decreased in the constructed wetland output. An infiltration rate also significantly decreased due to compaction of wetland soil. A runoff coefficient was increased due to the low infiltration rate after 2005. A T-N, TSS and Chl.a removal rate was maintained constantly. However, the T-P removal rate was slightly decreased along to wetland operation because low DO concentration could increase elution of phosphorus from sediment. After constructing open water, the T-P removal rate was increased. This is because open water could accelerate the reaearation process. Consequently, over three years of vegetation development could be helpful for wetland performance. In addition, DO concentration is important factor to maintain the T-P treatment.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2004년도 춘계 학술발표대회 개요집
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• pp.316-318
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• 2004

In recent years, plastic waste has been recognized as a worldwide environmental issue. To solve the disposal problem of the plastic waste, alternative treatment such as the use of biodegradable plastic(polybutylene succinate: PBS) is indeed highly in demand due to its merit of PBS buried in soil decomposed into carbon dioxide and water. In the present study, for the production of further functional PBS with TiO$_2$ as photocatalyst, which shows the decomposition of detrimental organic compound and pollutant under ultraviolet irradiation, we attempted to prepare photocatalytic TiO$_2$ coatings on PBS substrate by HVOF and plasma spraying techniques under various conditions using three kinds of agglomerated powders (P200: 200nm, P30: 30nm, P7: 7nm). The microstructures of coatings were characterized with SEM and XRD analysis, and the photocatalytic efficiency of coatings was evaluated through the photo degradation of gaseous acetaldehyde. Therefore, such functional TiO$_2$-Plastic composite material is expected to considerably contribute to the reduction of aggravated environmental problem.

• 에너지공학
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• 제27권1호
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• pp.76-80
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• 2018

The objective of this research paper is to discuss the waste coffee residue disposal and its environmental effects on the environment. As we know, coffee is one of the most demand and swallowed beverages in the world, which leads to large quantities of solid waste. Which can be toxic and a lot of environmental problems occur. In developing countries, there is a lack of proper coffee waste residue management. The coffee beans and residues contain several organic compounds. The wastewater from coffee industry emitted several pollutants (highly concentrated) and it contaminates the soil, ground waters, aquatic life, and also human health. Hence it is essential to treat the coffee waste residues. Mean while, oyster shell waste and its disposal also a big environmental challenge in the coastal regions of southeast Korea. In this paper, we focused the treatment of coffee waste residue with oyster shell waste powder. Primarily, oyster shells are calcinated at higher temperatures and investigated the calcined CaO powder as an anti microbic agent to the bacteria presented in coffee waste residues. We successfully applied calcium oxide from oyster shell waste, as an antimicrobic agent.

• 한국미생물·생명공학회지
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• 제5권1호
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• pp.29-35
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• 1977

주유소 공장주변의 하수 및 토양으로부터 Methanol 자화성 효모 7주를 분리하고 그중 생장이 완성한 균주 2주에 대하여 분류학적 제성질을 검사한 결과 양주는 모두 Candida속으로 동정되었다. 양주는 모두 ethanol 자화성을 가지고 생육에는 Biotin을 요구하였으며 배양특성은 최적온도 28$^{\circ}C$, 최적 pH5.0이고 methanol 농도 1%에서 중식이 균체수율은 대소비 methanol에 대하여 35~40%에 달하였다.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.439-447
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• 2015

The objective of this study was to isolate and identify the chemical structure of a biosurfactant produced by Nocardia farcinica strain BN26 isolated from soil, and evaluate its in vitro antitumor activity on a panel of human cancer cell lines. Strain BN26 was found to produce glycolipid biosurfactant on n-hexadecane as the sole carbon source. The biosurfactant was purified using medium-pressure liquid chromatography and characterized as trehalose lipid tetraester (THL) by nuclear magnetic resonance spectroscopy and mass spectrometry. Subsequently, the cytotoxic effects of THL on cancer cell lines BV-173, KE-37 (SKW-3), HL-60, HL-60/DOX, and JMSU-1 were evaluated by MTT assay. It was shown that THL exerted concentration-dependent antiproliferative activity against the human tumor cell lines and mediated cell death by the induction of partial oligonucleosomal DNA fragmentation. These findings suggest that THL could be of potential to apply in biomedicine as a therapeutic agent.

• 약학회지
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• 제37권4호
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• pp.389-396
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• 1993

An Actinomycetes strain JB isolated from Mt. Hanla had a strong antimicrobial activity against gram positive bacteria and tumor cell growth inhibition. Especially, it couldn't degrade starch and casein as organic compounds. It was resist on lincomycin and rifampicin. The spore mass of strain JB which was arethrospore was white. DAP of the cell wall was L, L-DAP. Antimicrobial material was heat stable, dissolved in ethyl acetate, and not dissolved in butanol. In the pressnce of 0.1% phenol and 4% sodium chloride, strain JB could grow, but it didn't growth at below $10^{\circ}C$. Strain JB didn't use dextran, sodium acetate and sodium citrate as sole carbon source and L-cystein and L-thereonine as nitrogen source. The filtered broth of strain JB had the antimicrobial activity against gram positive bacteria, especially Staphylococcus aureus (ATCC 65389) and the growth inhibition of tumor cell line.

• 농업과학연구
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• 제49권4호
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• pp.971-978
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• 2022

Fertigation, which has been introduced in agricultural fields since 1990, has been widely practiced in upland fields as well as in plastic film houses as part of the crop production system. In accordance with demands in the agricultural sector, a huge number of scientific studies on fertigation have been conducted worldwide. Moreover, with a combination of advanced technologies such as big-data, machine learning, etc., fertigation is positioned as an indispensable tool to achieve sustainable crop production and to enhance nutrient and water use efficiency. In this review, we focused on providing valuable information in terms of crop production and nutrient/water use efficiency. A variety of fertigation studies have described that enhancement of crop production did not differ relative to conventional method or slightly increased. In contrast, fertigation significantly improved nutrient/water use efficiency, with a reduction in use ranging from 20 to 50%. Water-soluble organic resources such as livestock manure and agricultural byproducts also have been identified as useful resources like chemical fertilizers. Furthermore, the initial irrigation point was generally recommended in a range of -10 - -40 kPa, although the point differed according to the crop and crop growth stage. From this review, we suggest that fertigation, which is closely integrated with advanced technology, could be a leading technology to attain not only food security but also carbon neutrality via improvement of nutrient/water use efficiency.

• 한국환경과학회지
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• 제21권8호
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• pp.989-996
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• 2012

Nitrate contamination of water environments can create serious problems such as eutrophication of rivers. Conventional biological processes for nitrate removal by heterotrophic denitrification often need additional organic substrates as carbon sources and electron donors. We tried to accelerate biological denitrification by using bioelectrochemical reactor (BER) in which electrode works as an electron donor. Denitrification activity of 8 environmental samples from various sediments, soils, groundwaters, and sludges were tested to establish an efficient enrichment culture for BER. The established enrichment culture from a soil sample showed stable denitrification activity without any nitrite accumulation. Microbial community analysis by using PCR-DGGE method revealed that dominant denitrifiers in the enrichment culture were Pantoea sp., Cronobacter sakazakii, and Castellaniella defragrans. Denitrification rate ($0.08kg/m^3{\cdot}day$) of the enrichment culture in BER with electrode poised at -0.5 V (vs Ag/AgCl) was higher than that ($2.1{\times}10^{-2}kg/m^3{\cdot}day$) of BER without any poised potential. This results suggested that biological denitrification would be improved by supplying potential throughout electrode in BER. Further research using BER without any organic substrate addition is needed to apply this system for bioremediation of water and wastewater contaminated by nitrate.