• 한국화재소방학회논문지
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• 제20권4호
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• pp.98-104
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• 2006

원자력발전소 화재방호 규정에서 방화벽 관통부는 방화벽과 동등한 내화성능을 갖는 구조로 시공할 것을 요구하고 있다. 화재방호 규정이 제정되기 이전에 설계되어 방화벽 관통부 내화성능 인증되지 않은 'K' 원자력발전소에 대해서 내화성능을 평가하였다. 내화성능 평가는 육안점검에 의한 방법과 시공된 관통부 데이터와 시험체 데이터를 비교하여 판단하는 한계접근법을 적용하였다. 내화성능 평가 결과, 전체 관통부의 50%에 해당하는 관통부가 성능기준에 미달하는 것으로 나타났다. 본 연구에서는 성능평가 결과와 더불어 관통부 내화성능을 확보하기 위한 설비 개선, 유지관리 방안 등을 제시하였다. 본 연구는 가동중인 발전소를 대상으로 한 실증평가로서 본 연구에서 적용한 평가방법, 연구결과 등은 향후 타원전의 관통부 성능평가에 유용하게 활용될 것으로 기대된다.

• 한국전산구조공학회논문집
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• 제32권2호
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• pp.133-140
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• 2019

본 논문은 Shaped charge jet(SCJ)의 관통 과정을 유한요소해석을 통해 모사하여 제트 입사속도, 관통률 그리고 관통량 증분과 같은 물리량들을 획득하였다. 이 물리량들을 hydrodynamic 이론에 적용하여 입사 제트 속도의 효율을 분석한 결과, 입사 속도가 빠른 제트의 관통 효율은 이어지는 느린 제트에 비해 높은 것을 확인하였다. 이 효율은 hydrodynamic limit(HL) 미만인 제트인 경우 큰 폭으로 감소하였다. 한편, 시간에 따른 관통량 증분과 제트 소모량의 비교는 SCJ의 이론적인 관통현상 분석을 위해서는 길이 연장 효과를 고려해야함을 보였다.

• 한국지반환경공학회 논문집
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• 제22권1호
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• pp.13-20
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• 2021

A suite of 3D large deformation finite element (FE) analyses was performed to investigate the load transfer mechanism and penetration resistance of spudcan foundations in heterogeneous soil profile consisting of sand and clay. The Elasto-Plastic models following Mohr-Coulomb and Tresca failure criteria were adopted for sand and clay, respectively. The accuracy of the numerical model was validated against centrifuge test measurements. The dense sand behavior with dilation is modeled using the non-associated flow rule. An investigation study consisting of key parameters, which includes variation in soil stratigraphy (sand-clay, sand-clay-sand), strength parameters of sand and clay (��' and su) and normalized height ratio of the sand layer (Hs/D) was conducted to assess the penetration behavior of spudcan. Based on calculated outputs, it was demonstrated that these parameters have a significant influence on the penetration resistance of spudcan. The calculated penetration resistance profiles are compared with the published (sand overlying clay) analytical model. It is confirmed that for the case of two-layer soil, the available theoretical model provides an accurate estimate of peak penetration resistance (qpeak). In the case of three-layer soil, the presence of a third stiff layer affects the penetration resistance profile due to the squeezing of the soil.

• Geomechanics and Engineering
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• 제24권1호
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• pp.1-14
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• 2021

In this study, a new approach using electrical resistivity measurement was proposed to detect grout penetration and to evaluate the grouting performance for such as waterproof efficiency in single rock fracture. For this purpose, an electrical resistivity monitoring system was designed to collect multi-channel data in real time. This was applied to a system for grout injection/penetration using a transparent fracture replica with various aperture sizes and water-cement mix ratio. The electrical resistivity was measured under various grout penetration conditions in real time, which results were directly compared to the visual observation images of grout penetration/distribution. Moreover, the grouting success status after the curing process was evaluated by measuring the electrical resistivity in relation to changes in frequency in fracture cells where grout injection and penetration were completed. Consequently, it was determined that the electrical resistivity monitoring system could be applied effectively to the detection of successful penetration of grouting into a target area and to actual field evaluation of the grouting performance and long-term stability of underground rock structures.

• Journal of the Korean Wood Science and Technology
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• 제10권3호
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• pp.135-151
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• 1982

In order to investigate the effectiveness of Osmose process for the practical treatment of wood this study has been made using water soluble preservatives such as Malenit and chromated zinc chloride. The results obtained in this investigation are as follows: 1. The penetration of Malenit in sapwood has been observed deeper than that of chromated zinc chloride for all species tested in this investigation. 2. The penetration of preservatives applied in soft wood, ie. Pinus densiflora and Larix leptolepis has been observed better results than that of hard wood, i.e., Quercus accutissima and Carpinus laxiflora. 3. The longer stack covering, despite of preservatives applied and size of wood tested, has given better penetration for all species tested, and the fastest diffusion has been occured in 15 days from they day started. Following after 15 days diffusion had gradualy become slower. 4. The length of time needed for effective penetration has taken 45 days for all species tested, reaching twenty millimeters (20mm) in depth in case of Malnit, that means also more than 50% of penetration into sapwood portion. However it has taken 45 days fer Pinus densiflora and Larix leptolepis, reaching fifteen millimeters (15mm) and 60 days for Quercus accutissima and Carpinus laxiflora, reaching same fifteen millimeters in case of chromated zinc chloride, that means also less than 50% (except 50% for Larix) of penetration into sapwood portion. 5. Deeper penetration of preservatives from the wood surface has been observed in the larger wood than the smaller wood for all species tested, although the penetration ratio between the width of sapwood and the length penetrated has been observed smaller in larger wood than smaller wood. 6. The relation between moisture content of wood and the penetration of preservatives into wood tested has shown the linear regression, that is, the more moisture content brought the deeper penetration. 7. Following the result obtained at this investigation osmose process with Malenit applied has indicated as a useable process for the none pressure treatment of wood.

• Journal of Pharmaceutical Investigation
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• 제36권6호
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• pp.385-392
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• 2006

Paclitaxel is an important chemotherapeutic agent for the treatment of human solid tumors. Multicellular resistance(MCR) is considered to be a major mechanism of resistance of human solid tumors to chemotherapeutic agent such as paclitaxel, which includes barriers to drug penetration through tumor tissues. Multicellular layers(MCL) cultures resemble in vivo tumor condition in terms of MCR and has been used successfully to produce clinically relevant data. In the present study, we evaluated the penetration characteristics and post-penetration anti-proliferative activity of paclitaxel using MCL of human colorectal cancer cells(DLD-1 and HT-29) grown in Transwell inserts. The penetration of $[^{14}C]-paclitaxel$ was slower than that of mannitol which penetrates via paracellular pathway in DLD-1 MCL. The penetration of $[^{14}C]-paclitaxel$ was faster in HT-29 MCL compared to DLD-1 MCL, i.e., at 10 ${\mu}M$ 100% and 40% penetration were observed after 48 hr incubation for HT-29 and DLD-1 cells, respectively. When calculated using anti-proliferative activity in the conditioned media of bottom chamber, the penetration after 24 hr was very limited(less than 50%) and concentration-dependent at the concentrations tested in both MCL's. These results suggest that limited and differential penetration of paclitaxel in tumor tissues may contribute to lower and differential efficacy against human solid tumors.

• 터널과지하공간
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• 제30권3호
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• pp.193-213
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• 2020

사용후핵연료 심층처분장 처분공에 설치된 압축 벤토나이트 완충재가 처분공 내벽에 형성된 굴착손상영역 불연속면 내로 침투하는 현상을 보다 더 현실적으로 모사할 수 있는 수학적 모델이 개발되었다. 이 모델에서는 압축 벤토나이트의 침투를 평행 평판 암반 절리을 통한 Bingham 유체의 이동으로 가정한다. 개발된 모델에 의해 벤토나이트의 침투현상을 분석한 결과, 암반 절리를 통해 압축 벤토나이트가 침투하는 최대 깊이는 포화 압축 벤토나이트의 팽윤압과 암반 절리의 폭에 비례하며, 압축 벤토나이트의 항복강도에 반비례하였다. 압축 벤토나이트의 점도는 압축 벤토나이트의 침투 속도를 좌우하나, 최대 침투깊이에는 영향을 미치지 않는다.

• 대한조선학회지
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• 제6권1호
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• pp.35-42
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• 1969

Penetrations of arc welding electrades are different by changing welding conditions, welding speed of travel and current, even though quite same ones. Changing status of penetration is studied by changing welding speed of travel keeping welding current constant, at first, and by changing welding current keeping welding speed of travel which was obtained prior experiment constant, afterward. The F-100 4mm $\phi$ rods, E4301 class, which covering substance is mainly ilmenite and a domestic representative product of this class electrode, are used for this experiment. The Marquette's No.130 5/32"(4mm)$\phi$ rods, E6011 class, and No. 140 5/32"(4mm)$\phi$, E6013 class, which were produced in the United Stated, are used to compare penetration with F-100 at same welding conditions. The covering substance of Marquette's No. 130 rods is mainly cellulose, and belong to deep penetration arc welding electrodes, the covering material of another rods is titania, and a kind f shallow penetration rods. The result of this study is as follow : penetration of F-100, domestic ilmentite covering electrade, E4301 class, is between E6011 and E6013 of the United States products. At the lower range of welding current, penetration is closer to E6013 than E6011, at the higher range, closer to E6011 than another; and the value of penetration ranges $1.65{\sim}2.70mm$ for 4mm$\phi$ rods in the adequate current range. The changing status of penetration is showed by following experimental formula. $P=KE_v^{-\frac{2}{5}}1^{\frac{3}{2}}$

• 터널과지하공간
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• 제22권2호
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• pp.144-156
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• 2012

본 논문에서는 TBM의 굴진성능 평가를 위한 실내시험 중 하나인 압입시험의 시험과 결과 분석방법에 대하여 연구하였다. 압입시험은 암석의 굴진저항 및 취성도를 나타내는 여러 지수들을 산정하고 이를 통해 TBM의 굴진율 및 추력을 직접적으로 추정할 수 있는 유용한 실험으로 알려져 있으나 국내에서는 아직 관련된 연구가 수행된 바 없으며 규격화된 시험방법이나 결과해석방법 역시 제시되지 못하고 있는 실정이다. 본 연구에서는 압입시험의 시험 장비를 재구성하여 제작하였고 다양한 조건에 대하여 시험을 수행하여 합리적인 시험방법과 시편의 크기에 대하여 고찰하였다. 또한 국내의 6개 암종에 대하여 압입시험을 수행하고 하중지수의 산정방법에 대하여 연구하였으며 하중지수로써 PLI와 MLI를 제안하였다. 본 연구에서 제안된 지수인 PLI와 MLI는 동일한 암종을 대상으로 수행된 선형절삭시험결과와 밀접한 상관관계를 보였으며 하중지수를 통해 개략적으로 예측된 단일 디스크커터의 수직하중은 실험값과 10% 오차를 보였다. 압입시험은 TBM의 성능예측을 위한 유용한 실험법임을 확인할 수 있었으며 본 연구는 이를 위한 기초연구로서 그 활용도가 높을 것으로 기대된다.

• Clinical and Experimental Reproductive Medicine
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• 제19권2호
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• pp.153-162
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• 1992

To solve the logistical problems of the sperm penetration assay (SPA) to provide just a sufficient number of hamster ova exactly when they are needed, a new method to cryopreserve the ova has been devised (1-step dehydration and 2-step thawing). After freezing & thawing of zona-intact (ZI) and zona-free (ZF) hamster ova according to this new method, the frozen-thawed ova were compared with fresh, control ova (FO) in terms of the degree of sperm penetration in SPA using semen samples from fertile donors, subfertile, and infertile male. Each sperm sample was capacitated for 42 hours inTEST-Yolk Buffer before insemination in SPA. In fertile doner, both the penetration rate and penetration index were lower in SPA using frozen ova (ZI; 92.4%, 6.2, ZF; 63.7%, 3.9) than those of SPA using fresh ova (99.3%, 8.4). There was a significant correlation between the penetration index of SPA using FO and ZI (p<0.001), and between those of SPA using FO and ZF and ova (p<0.001). In subfertile patient, both the penetration rate and penetration index were lowered in frozen ova (ZI; 62.3%, 1.3, ZF; 21.8%, 0.4) than those of fresh ova (74.8%, 1.8). There were significant correlation between the penetration rate and penetration index in ZI ova (p<0.05 and p<0.001, respectively). In infertile patient, both the penetration rate and penetration index were ZI; 3.1%, 0.0, ZF;0.0%, 0.0, respectively. There were significant correlation between the penetration rate and penetration index in ZI ova (p<0.05).