• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 기초기술학술발표회
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• pp.11-29
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• 2002

Current design of pile group is based on the estimation of the overall bearing capacity of a pile group from that of a single pile using a group efficiency. However, the behaviors of a pile group are influenced by various factors such as method of pile installation, pile-soil-pile interaction, cap-soil-pile interaction, etc. Thus it is practically impossible to take into account these factors reasonably with the only group efficiency, In this paper, a new method for the design of pile groups is proposed, where the significant factors affecting the behavior of a pile group are considered separately by adopting several efficiencies. Furthermore, in the proposed method, the load transfer characteristics of piles and the difference of pile behaviors with respect to the pile locations in group can be taken into account. The efficiencies for the method are determined using the settlement failure criterion, which is consistent with the concept of allowable settlement for structures. The efficiencies calculated from the results of existing model tests are presented, and the bearing capacity of a pile group in the other model test is calculated and compared with that from the test result, to verify the validity of the proposed method.

• 미생물학회지
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• 제52권2호
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• pp.226-229
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• 2016

먹물버섯 Coprinellus congregatus의 버섯조직이 자가분해되는 시기에 발현되는 chitinase (Chi2)는 사람에게 질병을 일으키는 Cryptococcus neoformans의 세포벽 두께를 정상 세포벽의 32% 수준까지 감소시킬 뿐만 아니라, 세포 외 섬유상 물질도 제거하였다. Chi2 처리에 의하여 사람에게 알레르기를 유발하는 Alternaria alternata의 생장은 물론 생쥐 모델에서 이 균에 의한 피부알레르기 증상도 감소시켰다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제8권1호
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• pp.35-41
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• 2003

캡이 설치된 준설퇴적토층에서 확산에 의한 오염물질이동을 측정할 수 있는 실내 실험방법들이 있지만, 확산에 의한 오염물질이동은 캡핑효과에 큰 영향을 미치지 않는다. 반면, 캡이 설치되는 동안이나 후에 퇴적층의 압밀에 의해 오염물질이 훨씬 더 많이 이동한다. 이것을 증명하기 위해, 원심모형시험기를 이용한 모형실험이 실시되었다. 본 연구에서 22.5시간 100 g에 대해 축소모형실험을 실시하였는데, 이것은 실제로 25년의 오염원이동시간과 축소모형의 100배 규모에 해당되는 모델링이라고 할 수 있다. 원심모형 실험결과 압밀에 의한 이류와 분산이 오염원 이동의 주 원인임을 알 수 있었다.

• 한국물환경학회지
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• 제32권2호
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• pp.216-221
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• 2016

The adsorption characteristics of mixed heavy metals (Cr(III), As(VI)) in aqueous solution were investigated using a sediment amendment composite. Sediment amendment composite was composed of clean sediment (40%), zeolite (20%), recycled aggregate (10%), steel slag (10%), oyster shell (10%), and cement (10%). The experimental results showed that the adsorption equilibrium was attained after 180 mins. Heavy metal adsorption was characterized using Freundlich and Langmuir equations. The equilibrium adsorption data for the sediment amendment composite better fitted with the Langmuir model than the Freundlich model. The maximum adsorption capacity of Cr(VI) (36.07 mg/g) was higher than As(III) (25.54 mg/g); and the adsorption efficiency of the Cr(VI) and As(III) ions solution decreased with decreasing pH from 2 to 10. The collective results suggested that the sediment amendment composite is a promising material for a reactive cap that controls the release of Cr(VI) and As(III) from contaminated sediments.

• Current Applied Physics
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• 제18권11호
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• pp.1388-1392
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• 2018

Metal thin films are used widely to solve the vibration problem. However, damping mechanism is still not clear, which limits the further improvement of the damping properties for film and the development of multi-functional damping coating. In this paper, Damping microscopic mechanism of porous metal films was investigated at both macroscopically and microscopically mixed levels. Molecular dynamics simulation method was used to model and simulate the loading-unloading numerical experiment on the micro-pore and vacancy model to get the stress-strain curve and the microstructure diagram of different defects. And damping factor was calculated by the stress-strain curve. The results show that dislocations and new vacancies appear in the micro-pores when metal film is stretched. The energetic consumption from the motion of dislocation is the main reason for the damping properties of materials. Micro-mechanism of damping properties is discussed with the results of in-situ experiment.

• Current Applied Physics
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• 제18권11호
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• pp.1368-1374
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• 2018

In this paper, forced vibration was used to regulate the droplet migration, fully recording the transient migration of droplets on a micro-textured substrate under the resonance frequency by a high-speed camera. The influence of resonance frequency and dynamic migration characteristics of droplets on the solid micro-texture surface under lateral vibration were researched. The experiment demonstrates that the driving force is caused by the difference between the left and right contact angles made the droplet oscillate and migrate, and as time t increases, the left and right contact points are periodically shifted and the amplitude of migration increases. Therefore, based on the droplet migration behavior and its force balance mechanism, a spring vibration model of migration behavior of the vibrating droplet micro unit was set up to predict the complete trajectory of its migration on a solid surface. The calculation results show that the theoretical displacement is less than the experimental displacement, and the longer the time, the larger the difference. Affected by the vibration, part of the droplet permeates through the micro-texture, resulting in the droplet losing height and the contact angle becoming smaller as well. While the other part of droplet overcomes the internal surface tension to migrate.

• Structural Engineering and Mechanics
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• 제85권3호
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• pp.407-417
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• 2023

Precast assembled bridge piers with hybrid connection (PASP) use both tendons and socket connections. To study the seismic performance of PASP, a full-scale in-situ test was performed based on an actual bridge project. The elastic-plastic fiber model of PASP was established using finite element software, and numerical analyses were performed to study the influence of prestress degree and socket depth on the PASP seismic performance. The results show that the typical failure mode of PASP under horizontal load is bending failure dominated by concrete cracking at the joint between the column and cushion cap. The cracking of the pier concrete and opening of joints depend on the prestress degree and socket depth. The prestressing tendons and socket connection can provide enough ductility, strength, restoration capability, and bending strength under small horizontal displacements. Although the bearing capacity and post yield stiffness of the pier can be improved to some extent by increasing the prestressing force, ductility is reduced, and residual deformation is increased. Overall, there are reasonable minimum socket depths to ensure the reliability of the socket connection.

• 자원ㆍ환경경제연구
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• 제25권3호
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• pp.421-447
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• 2016

본 논문은 온실가스 저감 정책인 탄소세 정책과 배출권거래제 정책을 통해 창출되는 경제지대를 획득하기 위한 집단 간의 혹은 집단 내의 경쟁 상황을 분석한다. 집단 간의 경쟁상황인 탄소세 정책에 대해 구성원들이 결정하는 성과보수를 공시하는 경우와 공시하지 않는 경우로 나누어 분석하여, 배출권거래제 정책과 후생을 비교한다. 본 논문에서 나타난 결과는 다음과 같다. 첫째, 본 논문은 집단들이 성과보수를 공시하는 경우 집단 간의 과열경쟁으로 인해 탄소세 정책이 배출권거래제 정책보다 항상 후생이 작게 된다. 둘째, 집단들이 성과보수를 공시하지 않을 경우, 탄소세 정책의 집단 간의 경쟁이 완화되어 탄소세 정책의 후생이 증가한다. 만약 배출권거래제 정책의 오염배출권 거래량이 상당히 많은 경우에는 오히려 탄소세 정책의 후생이 배출권거래제 정책보다 더 크게 된다는 것을 보였다.

• 한국물환경학회지
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• 제24권1호
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• pp.7-18
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• 2008

The objective of this study was to develop and apply a water quality simulation model for the evaluation of ungaged watershed. The Modified WASP5 consisted of three sub-models, LOAD-M, DYN-M, and EUT-M. LOAD-M, an empirical model, estimates runoff loadings using point and non-point source data of villages. Daecheong Dam watershed was selected for the research to calibrate, verify and application of Modified-WASP5. LOAD-M model was established using field data collected from all items of water quality and water quantity gaging stations of the watersheds, and was applied to the ungauged watersheds, taking the watershed properties under consideration. The result of water quality simulation using ModifiedWASP5 shows that the observed BOD data of Yongpo and Daechong Dam in 1999 were 0.8 mg/L and 1.0 mg/L, and simulated data were 0.9 mg/L and 0.9 mg/L, respectively. In case of 1999, average BOD concentrations were 0.8 mg/L and 1.0 mg/L. Simulated concentration showed 1.1 mg/L and 1.5 mg/L, respectively. Generally, the simulation results were in good agreement with the observed data. This study was focused on formulating an integrated model for evaluating ungauged watersheds. Even though simulation results varied slightly due to limited availability of data, the model developed in this study would be a useful tool for the assessment and management of ungauged watersheds.

• 생명과학회지
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• 제31권1호
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• pp.83-89
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• 2021

개불 라이소자임(Uu-ilys)은 개불(Urechis unicinctus)로부터 정제된 무척추형 라이소자임으로 병원균에 대한 방어에 주요하게 작용하는 선천성 면역 물질이며, 비효소적 항균 활성을 가지고 있어 항균 활성을 지닌 유도체의 개발 가능성을 가지고 있다. 본 논문은 개불 라이소자임에서 유래된 항균 활성을 가지는 유도체의 디자인과 생산을 기술하고 있다. 여러 항균성 펩타이드(antimicrobial peptide, AMP) 데이터베이스에서 제공하는 항균성 펩타이드 예측 도구를 사용하여 개불 라이소자임에서 항균 활성을 가지는 부위를 예측하였다. 개불 라이소자임 C-말단의 절편이 항균 활성을 나타낼 것으로 예측되었으며, 이 펩타이드는 C-말단 절편, Uu-ilys-CF라 명명하였다. Uu-ilys-CF은 이형 발현 시스템인 TrxA-Uu-ilys-CF 퓨전 단백질을 사용하여 생산하였다. 만들어진 퓨전 단백질은 브롬화시안을 사용하여 메티오닌 잔기를 절단하였으며, 절단된 Uu-ilys-CF은 고성능액체크로마토그래피와 역상 컬럼인 CapCell-Pak C18을 사용하여 분리되었다. Uu-ilys-CF의 항균 활성을 조사하기 위해서 여러 균주(그람양성균 4개, 그람음성균7개, 진균 1개)를 사용하였다. Uu-ilys-CF의 항균 활성은 살모넬라에서 가장 높은 반응을 보였다. 비록 Uu-ilys-CF는 진균에 활성을 나타내지 않았지만, 사용한 균주들에서 넓은 범위의 항균 활성을 나타내었다.