콘크리트의 블리딩에 미치는 혼화재의 영향

황인성,文學龍,金光華,한천구 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

This study is to investigate the influence of contents of mineral admixture on bleeding of concrete. According to the results, as W/B increases, bleeding occurs rapidly at early age regardless of replacement of mineral admixture, and when slump and air content are kept equal, the amount of bleeding decreases proportionately with an increase of replacing ratio of fly ash and blast furnace slag powder. Bleeding speed is highest at 60 minutes after placing concrete, and grow slower after 180 minutes. Bleeding speed also grows high with an increase of W/B, and is lower in the case of fly ash than in the case of blast furnace slag powder.

콘크리트의 블리딩에 미치는 시멘트 제조사 및 분말도의 영향

金恩浩,文學龍,황인성,한천구 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

This study is to investigate the influence of the manufacturing company and fineness of cement on bleeding of concrete. According to the results, as fineness of comment increases, slump and air content of fresh concrete decrease, and setting time is shortened. The amount of bleeding abates with an increase of fineness, and it is confirmed that bleeding does not occur especially in the case of B8000. it is confirmed that bleeding does not occur. Bleeding speed is higher in the case of OPC A than in the case OPC B, and grows low with an increase of fineness. It also becomes highest at about 60 minutes, and shows slow tendency in W/C of 45% in comparison with W/C of 50%. And It is confirmed that relativity between fineness of cement and the final amount of bleeding is very favorable. As the properties of hardened concrete, compressive strength do not make much difference between OPC A and B is little, and increases with an increase of fineness.

고성능 콘크리트의 특성에 미치는 혼화재의 영향

배정렬,김은호,황인성,한천구 청주대학교 산업과학연구소 2002 産業科學硏究 Vol.20 No.1

This paper is a fundamental study on the influence on the properties of high peformance concrete by mineral admixture. According to the results, while the fluidity decreases with the increase of replacement ratio of silica fume, it increases with the increase of replacement ratio of the other mineral admixture. Air content shows decreasing tendency with the increase of replacement ratio of fly ash, and the compressive strength of FA-SF2 shows the highest score. And the drying shrinkage increases with the increase of replacement ratio of fly ash, but it does not show much difference with the increase of replacement ratio of blast furnace slag powder. The autogenous shrinkage increases with the increase of replacement ratio of blast furnace slag powder, silica fume, while it decrease with the increase of replacement ratio of fly ash or combination of fly ash and silica fume. Therefore, it is thought that the fluidity, the placeability and the strength will be improved and the crack caused by autogenous shrinkage will be reduced by use of fly ash and silica fume together when making the high performance concrete.

Comparison of Robust Methods for Shear Wave Speed Estimation by Simulation

Hao Yin,Dong C. Liu,Xin Liu 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.8

Mechanical properties of tissue are often related to the pathological state of tissue. Therefore, non-invasively measuring tissue stiffness has important clinical applications. With the assumption of isotropy, incompressibility and linearity, the shear modulus of tissue is related to its shear wave propagation speed. Acoustic radiation force from a focused ultrasound beam can be used to generate shear waves at the focal region within tissue, which propagate orthogonally to the direction of the pushing ultrasound beam. The shear wave speed can be estimated based on the so called time-to-flight principle. The shear wave arrival time determined at several lateral positions along the shear wave propagation path can be measured by the displacement profiles, which can be tracked using correlation-based method by pulse-echo ultrasound. This approach has been successively used with various modifications by several groups. The purpose of this study is to design a simulation method to generate the pulse-echo ultrasound signal, calculate the displacement profile in the spatial and time domain, and estimate the shear wave speed using RANSAC, Radon Sum and robust linear regression method, compare and analyze the algorithm performance of these methods.

Anti-tumor Activity and Apoptosis-regulation Mechanisms of Bufalin in Various Cancers: New Hope for Cancer Patients

Yin, Pei-Hao,Liu, Xuan,Qiu, Yan-Yan,Cai, Jian-Feng,Qin, Jian-Min,Zhu, Hui-Rong,Li, Qi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.11

The induction of apoptosis in target cells is a key mechanism for most anti-tumor therapies. Bufalin is a cardiotonic steroid that has the potential to induce differentiation and apoptosis of tumor cells. Research on bufalin has so far mainly involved leukemia, prostate cancer, gastric cancer and liver cancer, and has been confined to in vitro studies. The bufadienolides bufalin and cinobufagin have been shown to induce apoptosis in a wide spectrum of cancer cell. The present article reviews the anticancer effects of bufalin. It induces apoptosis of lung cancer cells via the PI3K/Akt pathway and also suppressed the proliferation of human non-small cell lung cancer A549 cell line in a time and dose dependent manner. Bufalin, bufotalin and gamabufotalin, key bufadienolides, significantly sensitize human breast cancer cells with differing ER-alpha status to apoptosis induction by the TNF-related apoptosis-inducing ligand (TRAIL). In addition, bufadienolides induce prostate cancer cell apoptosis more significantly than that in breast epithelial cell lines. Similar effects have been observed with hepatocellular carcinoma (HCC) but the detailed molecular mechanisms of inducing apoptosis in this case are still unclear. Bufalin exerts profound effects on leukemia therapy in vitro. Results of multiple studies indicate that bufalin has marked anti-tumor activities through its ability to induce apoptosis. Large-scale randomized, double-blind, placebo or positive drug parallel controlled studies are now required to confirm the efficacy and apoptosis-inducing potential of bufalin in various cancers in the cliniucal setting.

도시 하천 환경 관리를 위한 제외지 초기 강우 처리 및 저류 시설 종합 관리 시스템 개발

윤진호(Zhen Hao Yin),구영민(Young Min Koo),이은형(Eunh Young Lee),서동일(Dong Il Seo) 大韓環境工學會 2015 대한환경공학회지 Vol.37 No.2

도시지역의 소하천은 불투수 면적의 증가 및 우수관거의 발달로 인해 유역의 오염물질 및 강우 유출수의 유달률이 증가한 반면 비강우시에 현저하게 유량이 감소되어 하천환경에 심각한 문제를 나타내고 있다. 본 연구에서는 도시 하천의 유 량과 수질 문제를 저감하기 위해 개발된 초기강우 저류 및 처리시설을 효율적으로 운영하기 위해 SWMM 도시유역모델 적용 결과와 자동모니터링 시스템을 이용하는 종합관리시스템을 개발하였다. 본 연구의 대상 지역인 관평천 유역의 대부분의 강 우사상에서 오염물질은 초기 4시간의 강우 유출수에 집중되어 있는 것으로 관찰되었으며 이는 처리시설의 용량 결정에 있어 가장 중요한 인자로 작용한다. 본 시험 유역에서 유역모델인 SWMM을 이용하여 계산한 결과 처리시설에서 수용할 수 있는 초기우수 유출량은 약 6 mm의 누적강우량으로 산정되었으며 이는 대상지역에서 발생하는 대부분의 소규모 강우에 대해 처 리가 가능하다는 것을 의미한다. 본 연구 결과는 강우-유출 모델과 연계한 초기우수 처리시설 운영을 위한 가이드라인을 제 시하고 있으며, 하천 수질 모델과 연결할 경우 유입하천에 미치는 영향을 사전에 예측할 수 있으며, 유역의 조건과 연계하여 도시하천의 유역연계 종합 수질관리를 위한 중요한 자료를 제공할 수 있을 것이다. Increase of delivery effect of pollutant loads and surface runoff due to urbanization of catchment area results in serious environmental problems in receiving urban streams. This study aims to develop integrated stormwater management system to assist efficient urban stream flow and water quality control using information from the Storm Water Management Model (SWMM), real time water level and quality monitoring system and remote or automatic treatment facility control system. Based on field observations in the study site, most of the pollutant loads are flushed within 4 hours of the rainfall event. SWMM simulation results indicates that the treatment system can store up to 6 mm of cumulative rainfall in the study catchment area, and this means any type of normal rainfall situation can be treated using the system. Relationship between rainfall amount and fill time were developed for various rainfall duration for operation of stormwater treatment system in this study. This study can further provide inputs of river water quality model and thus can effectively assist integrated water resources management in urban catchment and streams.

도시 소하천, 대전 탄동천, 수질개선 대안 수립을 위한 QUAl2K 수질모델 구축과 제외지 인공습지공법 적용 효율 평가

윤진호(Zhen Hao Yin),서동일(Dong Il Seo) 大韓環境工學會 2013 대한환경공학회지 Vol.35 No.3

도시의 하천은 주민의 생활공간의 일부로서 환경적인 지속성을 위해 자연 친환경적으로 관리함이 바람직하나 현재 홍수예방, 또는 조경공사에 가까운 하천정비만 되어 왔으며 하천의 수질보전 및 관리를 위한 지속가능한 수질관리 방안의 수립이 필요한 상황이다. 탄동천은 대전시 유성구 추목동을 기점으로 갑천으로 유입되는 지방 2급 하천이다. 상류에는 군부대, 중류는 주거단지, 하류는 국가주요 연구단지, 그리고 국가적인 규모의 문화시설이 공존하는 지역으로 소규모하천의 자연 친화적 관리에 매우 좋은 예가 될 수 있을 것으로 전망된다. 본 연구는 탄동천에 대한 수질조사를 진행하고 전면적인 진단을 해보았다. 그 결과 상류의 하수처리장 방류수와 신성교 부근의 관거유출수가 주오염원으로 발견되었다. 탄동천 수질개선을 위해서는 이러한 오염원들에 대한 관리가 필수이며 그 대책으로 하수처리장 고도처리시설 도입과 하수처리장과 신성교 부근의 하천둔치에 인공습지를 설계하여 수질개선을 제안하였으며 1차원 수질모델인 QUAl₂K를 이용하여 상술한 방안에 대한 수질개선 효과를 예측해 보았다. 모의결과 특히 T-P의 경우 0.05 mg/L 이하로 개선되는 것으로 모의되어 하천의 부영양화 방지에도 뚜렷한 효과가 있을 것으로 판단된다. 개선된 탄동천 수변공간은 인근 주민들에게 쾌적한 환경을 제공할 수 있으며 성공적인 수질관리 사례는 여타 하천관리의 설계, 시공에 큰 도움이 될 것이다. The Tandong-cheon stream is a 7.4 km long small urban stream that passes through Daeduk Science Town in Daejeon Korea. Despite the stream has great potential as an educational and recreational site due to its central location in the science town and science museums nearby, environmental aspect especially for water quality has not been evaluated properly. Through field survey, major pollution sources of the stream were identified and effect of water quality improvement alternatives were evaluated using a QUAl₂K water quality model for the stream. The study indicated that controlling major pollution sources of the stream alone may not be sufficient for reaching the water quality target. Therefore, additional pollution control methods are necessary. We applied the developed model to evaluate the effects of a constructed wetland on the terrace land, and analyzed whether the water quality target can be met at the outlet of the stream. It is expected that this study would provide a good reference for environmentally sound management of small urban streams in Korea.

수질관리 : 탄동천 유역의 지속가능한 수질관리 방안수립을 위한 조사연구

유진호 ( Zhen Hao Yin ),서동일 ( Dong Il Seo ),박병준 ( Byung Jun Park ),한종수 ( Jong Su Han ) 한국물환경학회 ( 구 한국수질보전학회 ) 2009 공동 추계학술발표회 Vol.2009 No.-

3차원 EFDC-WASP 연계모델을 이용한 경인아라뱃길 수질 예측

윤진호(Zhen Hao Yin),서동일(Dong Il Seo) 大韓環境工學會 2013 대한환경공학회지 Vol.35 No.2

경인아라뱃길은 한강하류와 서해를 잇는 국내 첫 인공운하이다. 아라뱃길 내에는 한강갑문으로부터 유입되는 담수와 서해갑문으로부터 유입되는 해수가 혼합됨으로써 염분 분포 및 성층특성이 발달되면서 복잡한 수리동역학적 특성을 나타낼 수 있으며 그에 따라 수질 특성도 크게 영향을 받을 것으로 판단된다. 본 연구에서는 운하 내의 염분 및 수온을 고려하여 3차원적인 수리동역학적 특성을 예측할 수 있는 EFDC (Environmental Fluid Dynamics Code)모델과 이에 따른 수질현상을 고려할 수 있는 WASP (Water Quality Analysis and Simulation Program)모델을 연계하여 사용함으로써 갑문 운영에 따른 3차원 시공간적 수리 및 수질특성을 예측할 수 있는 시스템을 구축하였다. 해수가 유입되는 서해갑문 측의 수질은 대체적으로 양호한 것으로 나타났으나 한강갑문 방향으로 이동할수록 수질은 점점 악화되는 것을 확인할 수 있었다. 또한 봄철 및 가을철에 경인아라뱃길 주운수로 내에서는 DO가 2mg/L 이하로 감소되는 등 빈 산소층이 형성되었으며, 체류시간 증가에 의한 BOD에 의한 DO소모가 가장 큰 원인으로 작용하는 것으로 추정된다. 따라서 운하 내의 빈산소 현상을 제어하기 위해서 자체적으로 BOD 농도를 개선하기 어려운 경우 수체의 체류시간을 단축시켜서 운영하는 방법을 선택하는 것이 바람직할 것으로 판단된다. Ara Canal is the first artificial canal in Korea that connects the Han River and the Yellow Sea. Due to mixture of waters with different salinity and water quality, complicated hydrodynamic and water quality distributions are expected to occur inside the canal. An integrated hydrodynamic and water quality modeling system was developed using the 3 dimensional hydrodynamic model, EFDC (Environmental Fluid Dynamics Code) and the water quality model WASP (Water Quality Analysis and Simulation Program). According to the modeling results, BOD, TN, TP and Chl-a concentrations inside the canal were lower at the West Gate side than the Han River side since influent concentrations of the West Gate side are significantly lower. Chemical stratification due to salinity difference were more evident at the West Gate side as vertical salinity difference were more pronounced in this area. On the other hand, Chl-a concentrations showed more pronounced vertical distribution at the Han River side as Chl-a concentrations were higher in this area. It was notable that Dissolved Oxygen concentrations can be lower than 2 mg/L occasionally in the middle part of the canal. While major factor affecting DO concentrations in the canal are inflows via both gates, the other important factor was found to be BOD decay in the canal due to extended hydraulic residence time. This study can be used to predict hydrodynamic conditions and water quality in the canal during the year and thus can be helpful in the development of gate operation method of the canal.

Triterpenoid saponins from Clinopodium chinense (Benth.) O. Kuntze and their biological activity

Yin-Di Zhu,Jing-Yi Hong,Feng-Da Bao,Na Xing,Ling-Tian Wang,Zhong-Hao Sun,Yun Luo,Hai Jiang,Xudong Xu,Nai-Liang Zhu,Hai-Feng Wu,Gui-Bo Sun,Jun-Shan Yang 대한약학회 2018 Archives of Pharmacal Research Vol.41 No.12

Four new ursane-type triterpenoid saponins, clinopoursaponins A–D (1–4), six new oleanane-type triterpenoid saponins, clinopodiside VII–XII (5–10), as well as eight known triterpene analogues (11–18), were isolated from the aerial parts of Clinopodium chinense (Benth.) O. Kuntze. The structures of the new compounds were determined based on extensive spectral analyses, including 1D (1H and 13C) and 2D NMR experiments (COSY, NOESY, HSQC, 2D TOCSY, HSQC-TOCSY and HMBC), HR-ESI-MS and chemical methods. Compounds 1–18 were evaluated for their protective effects against anoxia/reoxygenation-induced apoptosis in H9c2 cells and cytotoxicities against murine mammary carcinoma cell line 4T1. Compounds 8, 9 and 18 exhibited significant protective effects, while compound 1 exhibited cytotoxic activity with IC50 value of 7.4 μm compared to 7.6 μm for the positive control 10-hydroxycamptothecin.