• 한국식품영양학회지
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• 제10권4호
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• pp.559-563
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• 1997

장내유해세균에 대한 세균성 장내질환치료와 관련된 한약재의 항균활성 검색을 통해 우수한 효과가 인정된 가자를 선정하고 혐기적 broth system에서 각 용매별 분획물의 6종의 장내유해세균에 대한 항균활성을 측정하였으며 그 항균물질을 column chromatography 법에 의해 부분 정제하였다. 가자 메탄올 추출물은 100-2,000g/ml 농도에서 시험균 Eubacterium limosum ATCC 10825, Escherichia coli ATCC 25922, Bacteroides fragilis KCTC 5013, Clostridium perfringens ATCC 3627, Staphylococcus aureus KFCC 11764 및 Salmonella typhimurium ATCC 14028 모두에 대해 항균활성을 보였으며 특히 2,000g/ml 농도에서는 Escherichia coli ATCC 25922 및 Staphylococcus aureus KFCC 11764을 제외하고는 거의 생육하지 못하였다. 각 분획물(n-hexane, ethylether, ethylacetate 및 water)들간의 항균활성은 Clostridium perfringens ATCC 3627을 제외하고는 유의적인 차이가 없었다. 가자의 ethylacetate 분획은 Sephadex G-200 column chromatography에 의한 30개 분획 중 12에서 21번까지의 분획에서 강한 항균활성을 나타내었으며 silica gel column chromatography에 의한 40개 분획 중에서는 22에서 34까지의 분획에서 항균활성을 보였다.

• 상하수도학회지
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• 제31권6호
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• pp.577-586
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• 2017

One of the major sources causing eutrophication and algal blooms of lakes or streams is phosphorus which comes from point and nonpoint pollution sources. HAP (hydroxyapatite) crystallization using granular alkaline materials can achieve the decrease of phosphorus load from wastewater treatment plants and nonpoint pollution control facilities. In order to induce HAP crystal formation, continuous supply of calcium and hydroxyl ions is required. In this research, considering HAP crystallization, several types of lime-based granular alkaline materials were prepared, and the elution characteristics of calcium and hydroxyl ions of each were analyzed. Also, column tests were performed to verify phosphorus removal efficiencies of granular alkaline materials. Material_1 (gypsum+cement mixed material) achieved the highest pH values in the column tests consistently, also, Material_2 (gypsum+slag mixed material) and Material_3 (calcined limestone material) achieved over pH 9.0 for 240 hours (10 days) and proved the efficiencies of long-term ion supplier for HAP crystallization. In the column tests using Material_3, considerable pH increase and phosphorus removal were carried out according to each linear velocity and filtration depth. T-P removal efficiencies were 87.0, 84.0, 68.0% and those of PO4-P 100.0, 97.0, 80.0% for linear velocity of 1.0, 2.5, 5.0 m/hr respectively. Based on the column test results, the applicability of phosphorus removal processes for small-scale wastewater treatment plants and nonpoint pollution control facilities was found out.

• 한국지반공학회논문집
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• 제15권5호
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• pp.281-290
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• 1999

서해안과 남해안의 해안지역은 해성점토로 매립하여 부족한 용지를 확보하는 공사가 자주 시행되고 있다. 이렇게 새로이 생성된 연약지반을 개량하는 공법들은 아주 다양하다. 이중 외국에서 자주 사용되어온 생석회 말뚝공법은 국내에서는 거의 사용되고 있지 않다. 따라서 본 연구에서는 생석회 말뚝을 이용한 연약 지반개량공법을 국내 현장에 적용할 수 있도록 하기 위해 생석회 말뚝과 주변지반의 공학적인 현상을 규명하는데 초점을 맞추었다. 실내 모형시험과 유한요소해석을 실시하여 생석회 말뚝 주위의 압밀 현상을 파악하였다. 유한요소 해석 및 Chen 과 Law의 이론식에 의한 결과는 실제 발생하는 간극수압과는 일치하지 않았으나 전체적인 경향은 비슷하였다. 본 연구로부터 생석회 말뚝의 팽창압이 주위 지반의 압밀특성에 막대한 영향을 미치는 것으로 나타났다.

• 한국자원식물학회지
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• 제25권4호
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• pp.372-378
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• 2012

창이자 추출물을 이용하여 항산화활성 및 항균활성을 측정한 결과 다음과 같은 결론을 얻었다. DPPH를 이용한 항산화 활성 실험결과 VLC column로 분획한 XS-5에서 처리 농도 500 ${\mu}g/ml$에서의 87.53%로 가장 우수한 항산화 활성이 나타났으며, VLC로 분획한 XS-3-2의 처리농도 500 ${\mu}g/ml$에서 78.72%의 항산화 활성이 나타났다. PCL법으로 측정한 항산화 활성은 XS-1에서 13.32 nmol과 open column XS-3-2에서 14.34 nmol으로 항산화력을 나타났다. Candida albicans에 대한 항균활성은 XS-2의 처리농도가 500 ${\mu}g$/disc에서는 1 mm의 clean zone이 형성되었다. XS-3에서 DPPH와 PCL를 이용한 항산화 활성은 높았지만 항균활성은 낮게 나타났다. 창이자 추출물은 항산화 활성과 항균 활성은 상호 상관관계가 없는 것으로 판단된다.

• 산업기술연구
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• 제20권A호
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• pp.113-122
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• 2000

Column tests in the laboratory were preformed to investigate characteristics of settling process of dredged soil sampled from in-situ. Test results were analyzed by using the existing theories on discrete settling and hindered settling. From column tests of monitoring the interface with time, settling was found to be a linear process with time and the settling rate was increased with initial water content of slurry. The settling rate was also observed to decrease with increasing initial height of slurry. Most of settling process were composed of flocculation, hindered settling and self-weight consolidation. On the other hands, flocculation of soil during settling was observed and it was found that the size and density of flocculated particles could be analyzed by using the method proposed by Richardson and Zaki.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 추계학술대회 논문집
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• pp.128-131
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• 2001

The purpose of this study is to investigate the application of Column Jet Method(CJM) as countermeasure against settlement and slope sliding of existing marine structure due to embankment load behind reclaimed revetment. CJM is to make high-strengthened body by compacting and grouting cement mortar after forming artificial space in the ground with ground relaxition machine or high pressure water jetting. Before the ground was reinforced by CJM, the result of slope stability analysis was not satisfy the allowable safe ratio, but after the ground was reinforced by CJM, the stability of slope was over the allowable safe ratio and stable, Therefor, the application of CJM to restraint settlement and sliding of marine structure was very satisfactory.

• 한국안전학회지
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• 제17권3호
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• pp.118-122
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• 2002

토압 및 수압을 받는 지하외벽의 거동을 파악하기 위하여 유한요소를 이용한 수치적 연구를 수행하였다. 지하외벽의 구조설계는 판의 경계조건을 가정하여 이루어지는데 이 가정으로 인하여 잘못된 결과를 초래할 수 있다. 본 연구에서는 벽체와 기둥의 강성비와 형상비에 따른 모멘트와 전단력의 변화에 대한 변수해석을 수행하였다. 지하외벽의 설계에 적용할 수 있는 수정계수와 설계에의 적용예를 제시하였다.

• Nuclear Engineering and Technology
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• 제28권5호
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• pp.482-487
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• 1996

The dissolved oxygen removal by H$_2$-O$_2$ reaction in column packed with various catalysts wes examined. The catalysts employed were the prepared polymeric catalyst platinum on activated carbon, and Lewatit OC-1045 which is available commercially. The column experiments with the prepared polymeric catalyst showed the dissolved oxygen reduced to 35 ppb which is below the limit in feed water of power plants. This implies the likely application of the prepared catalyst for practical use. The activated carbon required the pre-treatment for the removal of dissolved oxygen, since the surface of activated carbon contains much oxygen adsorbed initially. The Lewatit catalyst exposed the best performance, however, the aged one showed the gradual loss of catalytic activity due to degradation of resin catalyst.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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• pp.592-595
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• 2009

In recent years, geothermal heat pump (GHP) systems have become increasingly popular for heating and cooling in buildings. The Standing Column Well (SCW) method is one of the most efficient GHP system. Because it use groundwater for heat transfer material. In SCW systems, water is re-circulated between the well and the building (heat pump). It is only a short time since this method has been applied in domestic. So we have to refer to the developed countries' guides and manuals of SCW. In this paper, several design and construction points of SCW method are filed. We used real operation data of SCW system at Chong-Ju Univ. site for economical efficiency analysis. As a result, the payback period of Chong-Ju Univ. site is calculated at 7.23 years.

• 대한기계학회논문집
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• 제11권4호
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• pp.629-636
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• 1987

An experiment is carried out to study the surface-tension driven flow characteristics in a cylindrical liquid column heated from above (which is the low gravity floating zone simulated on earth) with varing the aspect ratio and diameter of the liquid column. Hexadecane, octadecane, silicon oil(10cs), FC-40 and water are used as the test liquids. The free surface shape varies sinusoidally for Ma>M $a_{cr}$ and its frequency is found to be the same as that of temperature oscillation. It is verified that the surface temperature profile changes from linear to S-shaped profile for Ma>M $a_{cr}$ . The frequency of temperature oscillation decreases with increasing liquid volume, while its level increases. M $a_{cr}$ decreases with increasing aspect ratio, and also decreases with increasing Prandtl number in the range of 25