• 한국도로학회논문집
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• 제13권2호
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• pp.21-29
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• 2011

최근 들어 온난화 등의 영향으로 태풍이나 집중호우가 빈번히 발생하고 있으며 이로 인한 산지 도로의 산사태, 토석류, 상향침투수압 등에 의한 인명, 시설물 피해도 극심하게 나타나고 있다. 산지 도로의 상향침투수압은 심각한 포장 파손을 발생시키기도 한다. 산지 측의 높은 지하수위로 인한 상향침투수압을 감소시키기 위해서는 지하배수공법이 매우 효과적 이라고 판단된다. 지하배수 공법을 원활하게 작동하기 위해서는 배수기층이 적합한 투수계수와 지지력을 갖추어야 한다. 따라서 본 연구에서는 적절한 투수성과 지반 지지력을 확보할 수 있는 최적의 배수기층 입도에 대한 연구를 수행하였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2005년도 지반공학 공동 학술발표회
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• pp.382-388
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• 2005

Soil vapor extraction(SVE) is an effective and cost efficient method of removing volatile organic compounds(VOCs) and petroleum hydrocarbons from unsaturated soils. However, soil vapor extraction becomes ineffective in soils with low gas permeability, for example soils with air permeabilities less than 1 Darcy. Prefabricated vertical drains(PVDs) have been used for dewatering fine-grained soils for more than 25 years. Incorporating PVDs in and SVE system can extend the effectiveness of SVE to lower permeability soils by shortening the air flow-paths and ultimately expediting contaminant removal. The objective of the work described herein was to effectively incorporate PVDs into a SVE remediation system and to demonstrate a PVDs enhanced SVE system at full scale. The finding from this research will facilitate the design of field PVD-SVE systems in terms by providing insight into the optimal spacing between PVDs, the radius of influence of the wells and the flow rates to be used to capture and extract gas phase contaminants.

• Journal of Microbiology and Biotechnology
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• 제26권3호
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• pp.610-617
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• 2016

Candidiasis has posed a serious health risk to immunocompromised patients owing to the increase in resistant yeasts, and Candida albicans is the prominent pathogen of fungal infections. Therefore, there is a critical need for the discovery and characterization of novel antifungals to treat infections caused by C. albicans. In the present study, we report on the antifungal activity of the ethanol extract from Salvia miltiorrhiza against C. albicans and the possible mode of action against C. albicans. The increase in the membrane permeability was evidenced by changes in diphenylhexatriene binding and release of both 260-nm-absorbing intracellular materials and protein. In addition, inhibition of cell wall synthesis was demonstrated by the enhanced minimal inhibitory concentration in the presence of sorbitol and reduced (1,3)-β-D-glucan synthase activity. The above evidence supports the notion that S. miltiorrhiza has antifungal activity against C. albicans by the synergistic activity of targeting the cell membrane and cell wall. These findings indicate that S. miltiorrhiza displays effective activity against C. albicans in vitro and merits further investigation to treat C. albicans-associated infections.

• 산업기술연구
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• 제29권A호
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• pp.55-60
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• 2009

Stabilization treatment is one of processes for wastes and their components to reduce their toxicity and migration rates to surroundings. Inorganic binders such as calcium hydroxide, blast furnace slag and red mud were tested for their potential applicability to in-situ stabilization of heavy metal contaminated tailings in the abandoned metal mines. Columns(150mm dia. ${\times}$ 450mm length) filled with mixtures of inorganic binders and tailing from the Geumjang mine with various mixing ratios of binders to tailings, 5%, 7% and 9% were applied artificial rainfall tests for 28 days. Effluents from columns filled with calcium hydroxide and tailing showed high pH's of ~12.5 and a increasing trend of concentration in Pb and Zn with a significant decrease in permeability in terms of elapsed days. Those with burning slag and tailing showed pH's of ~8.5 and significantly low concentrations in heavy metals with a stable permeability. In case of red mud, effluents showed significantly low concentrations in heavy metals but a decreased permeability with pH's of ~10.5. Conclusively, this basic study suggests burning furnace slag be a potential stabilizer for effective treatment of heavy metal contaminated mine tailings.

• Geomechanics and Engineering
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• 제18권1호
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• pp.59-69
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• 2019

Grout injection is mainly used for permeability reduction and/or improvement of the ground by injecting grout material into pores, cracks, and joints in the ground. The oscillatory grout injection method was developed to enhance the grout penetration. In order to verify the level of enhancement of the grout, field grout injection tests, both static and oscillatory tests, were performed at three job sites. The enhancement in the permeability reduction and ground improvement effect was verified by performing a core boring, borehole image processing analysis, phenolphthalein test, scanning electron microscopy analysis, variable heat test, Lugeon test, standard penetration test, and an elastic wave test. The oscillatory grout injection increased the joint filling rate by 80% more and decreased the permeability coefficient by 33-68%, more compared to the static grout injection method. The constrained modulus of the jointed rock mass was increased by 50% more with oscillatory grout injection compared to the static grout injection, indicating that the oscillatory injection was more effective in enhancing the stiffness of the rock mass.

• 한국전자통신학회논문지
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• 제9권8호
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• pp.921-926
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• 2014

본 논문에서는 CSLR(Complementary Single Loop Resonator)을 이용한 인셋 급전 마이크로스트립 안테나의 특성에 대해 연구하였다. SLR(Single Loop Resonator) 단일 구조에서 시뮬레이션 셋업 과정을 통해 산란계수로부터 실효투자율을 계산하였으며, 실효투자율이 음의 값을 갖는 주파수에서 SLR 구조의 치수를 선택하였다. 그리고 인셋 급전된 마이크로스트립 안테나의 접지면에 SLR 구조의 쌍대 구조인 CSLR을 $3{\times}3$으로 배열하여 최적 안테나를 설계하였다. 설계한 안테나의 반사손실과 복사패턴을 구하였으며, 공진주파수 2.82 GHz에서 기존의 인셋 급전 안테나와 크기를 비교하면 면적 대비 약 56.8%가 감소하는 결과를 얻었다. 사용된 툴은 3차원 FEM 툴인 Ansoft사의 HFSS를 사용하였다.

• 대한한의학회지
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• 제20권2호
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• pp.177-186
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• 1999

Okbyungpoongsan(OBPS) has long been known to have anti-allergic effect. In order to evaluate the influence on innate and specific immune response, the effects of OBPS on vascular permeability. hypersensitivities and phagocytic functions were measured. As the results, OBPS increased phagocytic activity of peritoneal macrophages in vitro and in vivo. But OBPS depressed formation of reactive oxygen intermediates(ROI) in vitro and in vivo, while the drug enhanced generation macrophages. Foot pad swelling in the mouse and contact hypersensitivity against dinitroflouorobenzene were decreased. OBPS had no effect on NK cells. But OBPS decreased vascular permeability induced by histamine without statistical significance. These results demonstrate that OBPS suppresses hypersensitivity reactions without affecting phagocytic functions and formation of ROI from macrophages. It also means that OBPS acts as a effective inducer to synthesis of nitric oxide which is effective for the infectious disease while it does damage to tissue less as it suppresses ROI, So we can conclude that OBPS could be used for the treatment of the disease related with immune function.

• Geomechanics and Engineering
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• 제25권2호
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• pp.159-170
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• 2021

Particle size of tailings in different areas of dams varies due to sedimentation and separation. Saturated hydraulic conductivity of high-stacked talings materials are seriously affected by void ratio and particle breakage. Conjoined consolidation permeability tests were carried out using a self-developed high-stress permeability and consolidation apparatus. The hydraulic conductivity decreases nonlinearly with the increase of consolidation pressure. The seepage pattern of coarse-particle tailings is channel flow, and the seepage pattern of fine-particle tailings is scattered flow. The change rate of hydraulic conductivity of tailings with different particle sizes under high consolidation pressure tends to be identical. A hydraulic conductivity hysteresis is found in coarse-particle tailings. The hydraulic conductivity hysteresis is more obvious when the water head is lower. A new hydraulic conductivity-void ratio equation was derived by introducing the concept of effective void ratio and breakage index. The equation integrated the hydraulic conductivity equation with different particle sizes over a wide range of consolidation pressures.

• 한국수산과학회지
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• 제34권4호
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• pp.320-326
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• 2001

어분단백질의 이용성을 높이기 위한 가식성 혹은 생분해성 필름가공을 목적으로 알칼리 처리하여 제조된 FMPI의 물성과 이물성과 ester 화합물의 필름 투과율과 인장강도에 미치는 영향을 조사한 결과는 다음과 같다. 어분으로부터 알칼리처리하고 추출조건을 달리하여 제조된 FMPI의 추출량은 추출시간이 증가함에 따라 증가하였다. FMPI의 소수성은 추출시간 1시간일 때 가장 높게 나타났다가 그 이상 추출시간이 경과함에 따라 감소하였다 유화활성은 추출시간이 5시간까지 증가함에 따라 급격한 증가를 보였으며, 유화안정성은 추출시간 2시간까지 추출시간의 증가에 따라 급격한 감소를 보여 유화활성과 상반된 결과를 나타내었다. 점도는 pH가 2일 때 가장 높게 나타났고 pH가 4일 때 가장 점도가 낮게 나타났다. 첨가하는 가소제의 농도가 증가할수록 필름의 ethyl acetate의 투과도는 증가하였다. 가소제의 종류별에 따른 ethyl acetate의 투과도는 polyethylene glycol, glycerol 및 sorbitol 첨가 필름 순으로 높게 나타났으며, ester 화합물 중에서는 ethyl formate의 투과속도가 가장 높았다. 온도가 증가함에 따라 ethyl acetate의 필름 투과속도는 증가하였다. FHPI의 표면소수성이 증가하면 필름의 인장강도가 증가하였다. 필름의 신장율은 FMPI의 표면소수성보다 가소제의 종류에 더 큰 영향을 받았다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -1
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• pp.627-630
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• 2002

A methodology based on factorial design and Motto Carlo methods is developed and implemented for incorporating uncertainties within a multiphase subsurface flow and transport simulation system. Due to uncertainties in intrinsic permeability and longitudinal dispersivity, the predicted output is also uncertain based on the well-developed multiphase compositional simulator. The simulation results reveal that the uncertainties in input parameters pose considerable influences on the predicted output, and the mean and variance of permeability will have significant impacts on the modeling output. The proposed method offers an effective tool for evaluating uncertainty in multiphase flow simulation system.