경사지반에 위치한 교대기초의 원심모델링

유남재,전상현,홍영길 江原大學校 産業技術硏究所 2007 産業技術硏究 Vol.27 No.B

This paper is the research result about centrifuge model experiments of investigating the behavior of bridge abutment on the sloped ground. Ground condition of the studied site was the bridge abutment with pile foundation adjacent to the slope. The pile foundations was supported on the soft rocks covered with the embankment. Evaluating the behavior of such a complicate ground and structure conditions was not easy so that the centrifuge modelling was performed to find the overall behavior of them. Layout of centrifuge model experiment was simplified to simulate easily the actual behavior of very complicate site condition. Construction process in field such as ground excavation for footing foundation, installation of piles, Placement of footing and bridge abutment, backfilling and surcharge loading eas duplicated in the centrifuge model experiment, Consequently, the stability of the piled bridge abutment adjacent to the slope of embankment was evaluated throughout centrifuge modelling.

혈청이 마우스 간 세포주 BNL CL.2의 Nitric Oxide 생성에 미치는 영향

유지창,정헌택,김유현,진효상,김신무,배현옥 THE KOREAN SOCIETY FOR BIOMEDICAL LABORATORY SCIEN 1999 Journal of biomedical laboratory sciences Vol.5 No.1

마우스 간 세포주인 BNL CL.2의 시험관내 배양에서 혈청과 IFN-γ가 세포주의 nitric oxide(NO) 생성과 세포 손상에 미치는 영향을 알아보기 위한 실험을 하였다. 혈청이 공급된 배양에서 IFN-γ에 의한 세포 생존율은 거의 변동이 없었으나, 혈청을 제거한 배양에서는 약 65%의 생존율이 유지되었으며, NO 생성 억제제인 N -monomethy-L-arginine (NMA)의 첨가는 농도 의존적으로 세포의 생존율을 감소시켰다. 혈청이 제거된 BNL CL.2세포주는 IFN-γ단독 처리에서도 NO 를 생성할 수 있었으며, IFN-γ와 lipopolysaccharide (LPS)의 복합 처리는 세포주의 NO 생성을 상승적으로 증가시켰다. 또한 protein tyrosine kinase (PTK) inhibitor인 herbimycin A와 genistein에 의해서 NO 생성이 억제되어 PTK의 활성이 혈청이 고갈된 BNL CL.2 세포에서 NO의 생성에 중요한 역할을 담당하고 있기 때문으로 판단된다. IFN-γ의 독성은 혈청을 제거시킬 때 NO 생성 억제제에 상승적으로 간 세포를 손상시키며, 이때 NO가 IFN-γ에 의해 유도된 손상을 어느 정도 억제시키는 것을 알 수 있었다. Nitric oxide (NO) plays an important role in immunologic defense, and influences upon the functioning of secretory tissues and cells. It also exhibits cytotoxic/cytostatic activity as one of major operating effectors of the cellular immunity system. We investigated the effects of serum on the cell damages and NO production in the mouse liver cell line BNL CL.2 to establish the role of NO. We observed that, when BNL CL.2 cells were cultured in serum-free medium, they were induced to cell damage by the stimulation of IFN-γalone or IFN-γplus LPS. Serumstarved cells showed large amount of nitrite accumulation and NO synthase (NOS) expression in response to IFN-γalone in dose-and time-dependent manners, but serum-supplied cells did not. The production of NO was blocked by protein tyrosine kinase (PTK) inhibitors, genistein and herbimycin. These results suggest that the deprivation of serum in the BNL CL.2 cell culture medium might primed with the cells to produce NO when the cells are triggered by IFN-γ and the involvement of PTK signal transduction pathway in the expression of NOS gene in murine hepatocytes.

모래층 지반 안벽구조물의 탄성침하거동 연구

유남재,전상현,전진용 江原大學校 産業技術硏究所 2007 産業技術硏究 Vol.27 No.B

This paper is research results of investigating the elastic settlement behavior of the coastal caisson structure built on the sandy deposit by comparing results of centrifuge model experiments and those of existing methods of estimating elastic settlement. Basic soil property tests such as specific gravity test, grain size distribution test and organic content test with disturbed soil sampled from the site were carried out. The centrifuge experiment of model satisfying the required design criteria was performed under 50 of artificial accelerated gravitational force condition. The Centrifuge model experimental results were compared and analyzed with the current methods of estimating settlement based on the elastic modulus obtained from the results of odeometer tests and empirical methods from literature reviews.

안벽구조물에 대한 Centrifuge 모형실험과 수치해석

유남재,김동건,전상현 江原大學校 産業技術硏究所 2009 産業技術硏究 Vol.29 No.B

In this paper centrifuge model tests and numerical analysis on the coastal structure on the marine deposits of sand were performed to investigate the behavior of structure and foundation under the condition of wave action in field. In centrifuge model experiments, construction sequence of coastal structure such as preparation of sand deposit, excavation replacement, rubble mound with crushed stones and installment of coastal structure was reconstructed and the behavior of ground settlement during stage of construction was observed during tests. For the final stage of simulating the horizontal movement of coastal structure due to wave force, horizontal load was applied by horizontal loading apparatus being specially designed so that horizontal displacement of structure could be observed. Numerical analysis were also carried out and its results were compared with test results to assess the property of centrifuge mode experiments with respect to the behavior of structure as well as ground.

연약지반 위에 시공되는 교대의 측방유동에 대한 안정성 평가

유남재,김동건,전상현 江原大學校 産業技術硏究所 2010 産業技術硏究 Vol.30 No.B

In this paper stability about lateral soil movement of bridge abutment constructed on the soft ground, reinforced with the sand compaction pile (SCP) and the preconsolidaton methods, was evaluated by using the centrifuge testing facility which stress conditions in field could be reconstructed in the laboratory. The layouts of model such as ground condition, sand compaction piles and abutment was determined on the basis of similitude law with the reduced scale of 1/200. Construction sequences of installing SCP, preparing reclaimed ground, preconsolidating ground and building the piled bridge abutment were reconstructed during centrifuge modelling and measurements of movement were followed in each sequence. From analyzing the results of measuring movements of the model abutment and the ground, measured lateral movement of model abutment was found to be within the allowable value so that stability of abutment against lateral sliding was secured.

토사 절토사면 안정성 영향인자의 민감도 분석

유남재,박병수,전상현,조한기 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.B

A sensitivity analysis about effects of influencing factors on the stability of Soil cut slope was performed. Slope stability analyses were carried out under dry, rainy and seismic conditions. Dominant factors controlling the slope stability were chosen such as cohesion and internal friction angle, unit weight of soil, water table and seismic horizontal coefficient used for the slope stability during eurthquake. Parametric stability analysis with those factors was performed for sensitivity analysis. As results of analyzing the sensitivity of factors under dry and rainy conditions, effects of cohesion, internal friction angle and unit weight of soil on the stability of slope are more critical in the dry condition than in the rainy condition. Cohesion and internal friction angle are more dominant factors influencing the slope stability irrespective of dry or rainy conditions than unit weight of soil and the horizontal seismic coefficient. The unit weight and the horizontal seismic coefficient affects crucially the stability according to conditions of slope formation and dry or rainy seasons. For the effect of horizontal seismic coefficient on stability of slope, safety factor of slope is not affected significantly by dry or rainy conditions, However, increase of the horizontal seismic coefficient under the rainy condition does reduce the safety factor significantly rather than the dry condition. Therefore, it is needed that the location of the water table is assigned appropriately to satisfy the required safety factor of stability in the case of checking slope stability for the rainy and seismic conditions.

국균세포벽을 모델로 한 새로운 고정화담체의 개발

유은정,김종덕,송상호,임현수,최명락,정규화 여수대학교 1997 論文集 Vol.11 No.2

The purpose of this investigation was to develop a new carrier using chitin and glucan as the model for Aspergillus oryzae cell wall. In case of the ratio of chitin and glucan(3/1), the activity of the immobilized protease had higher than that of model(chitin/glucan=1/3) and carriers were formed gel. In case of soluble chitin and glucan treated with calcium carbonate, there were a 1.8-fold increase in activity of immobilized protease compared with untreated chitin. The scanning electron microscope image showed that a pore size of this carrier had a homogenized pore size and a smooth surface.

갓김치 ether 추출물의 발효 과정상의 생리 기능성 변화

유은정,임현수,최명락,송상호 여수대학교 1999 論文集 Vol.14 No.2

일반 김치의 경우 17±1℃에서 2일 사이에 pH가 4.0에 이르는 것에 비해 갓김치의 경우 18℃에서 저장한 경우에 14일 경에 pH가 4.0(Fig.1)에 이르러 일반 김치 보다 저장성이 3~5배 높은 것으로 나타났으며 총균수에서도 비슷한 양상을 나타내었다. 또한 간암세포에 대한 항암성에서 IC30의 농도가 발효기간별 시료 모두 1000㎍이상으로 나타났으며 발효 0일째 시료가 1000㎍에서 50%의 간암세포 사멸성을 나타내서 가장 항암효과가 우수한 것으로 나타났고, 간정상세포에 대해서는 1000㎍ 이상에서도 28% 이하의 사멸성을 나타내서 정상세포에 대해 큰 영향을 미치지 않는 것으로 나타났다. 또한 항산화 효과에 있어서는 초기(0~2일) 발효시 수소공여능이 53%로 나타나서 다른 식품 추출물의 항산화 효과에 비해서는 비교적 높은 효과를 나타내었다. 그러나 발효 14일에는 15%로 감소되어서, ethyl ether에 의해 추출되어 항산화 효과를 나타내었던 물질들이 발효가 진행됨에 따라 감소된 것으로 사료되었다. The anticancer and antioxidative effects of Mustard Leaf Kimch ether extracts according to various fermentation period were investigated. pH of the Mustard Leaf Kimchi was reached at 4.0 on 14th day, so the period reaching well-fermentating state was up to 3~5 times longer than that of ordinary Kimchi. The anticancer effect on HepG2 by the addition of fermented Mustard Leaf Kimchi ether extracts was higher than that on CCL-13. IC30 of Mustard Leaf Kimchi in HepG2 was showed more than 1000㎍.Especially, 50% of death ratio was showed in HepG2 cells by the addition of ether extracts(0 day). the other side. 28% of death ratio was shown in CCL-13 up to 1000㎍ of ether extracts. As well as the Mustard Leaf Kimchi ether extracts(0-2 days) showed higher antioxidative effect than of others. The hydrogen donor activity was 53% at initial fermentation period, but it was decreased at 14% on 14th day. So, ether soluble antioxidative materials in Mustard Leaf Kimchi was decreased during fermentation.

大型建築物의 合理的인 變電設備 容量基準에 관한 硏究

兪賢在,全勝九 大田工業大學 1992 한밭대학교 논문집 Vol.9 No.1

In this paper, we proposed the reasonable design standard of Demand Factor fo large office buildings, that was made by the statistical way considering autua conditions, such as investicated electric equipment capacity, electric power consumption etc. So as to save electric equipment investment, the decrease of power loss, the improvement of facilities utilization and the decrease of electric rates, we can be contribute by the application of the design standard. The result of saving effect is showed to confirm the practical use of the propose Demand Factor, and also, it is believed that this proposed Demand Factor will be useful in electric equipment operation and planning.

자연사면 산사태 특성에 관한 사례 연구

유남재,전상현,박남선 江原大學校 産業技術硏究所 2007 産業技術硏究 Vol.27 No.B

This paper is a result of a case study about landslides at Whacheon area in Kangwondo occurred during heavy rainfall in 2006. A-day-accumulative rainfalls from July 12 to July 13 and July 15 to July 16 were 120mm and llOmm respectively. Five sites at which slope failures occurred were visited to figure out main causes of slope failures by investigating characteristics of rainfall, geological forrnation, topography and ground surface exploration around the boundary of the landslides. Based on the site investigation characteristics of landslide with respect to rainfall pattern, geological and topographical condition and pattern of landslide were evaluated.