• Title/Summary/Keyword: Transport Pathway

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Analysis of Sediment Transport Pathway using the STA Method in Nakdong Estuary (STA 기법에 의한 낙동강 하구역의 토사이동경로 예측)

  • Yoon, Eun-Chan;Lee, Jong-Sup
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.20 no.6
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    • pp.540-552
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    • 2008
  • We predicted to seasonal sediment transport pathway of the estuary area of the Nakdong river using the STA method. The eCSedtrend model was used to flexible application of the previous STA methods. The analysis of the seasonal interpretation of sediment transport pathway showed that the most dominant trend in the Nakdong estuary was CB+ and CB-. In case of CB+, it was identified around the area where the mud sediment was distributed and formed transport vector toward the north. Also, in case of CB-, it was identified mostly around the sand bar where the sand sediment was distributed and generally showed transport vector toward the north even though there was seasonal difference.

Understanding and Their Application of GoldSim Transport Pathways to Mass Trasport Simulation (질량 이동 모사 프로그램 개발을 위한 골드심 이동 패쓰웨이의 이해와 활용)

  • Lee, Youn-Myoung;Jeong, Jongtae
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.12 no.2
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    • pp.135-151
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    • 2014
  • It is very important to properly understand such "Transport Pathways" elements as "Pipe" and "Cell" pathways in commercial GoldSim Transport Module (GTM) for developing higer quality models and programs for performance assessment of complex radioactive waste repositories. With an illustrative case under an earthquake scenario, by which an increasement in the groundwater flow rate occurs though the geological medium, ways of avoiding possible modeling errors in the nuclide transport modeling in the radioactive waste repository system for its safety assessment by utilizing such pathways are discussed and a proper usage of the pathways is proposed.

Effect of Simetryne on Chloroplast-Mediated Electron Transport and Photoacoustic Signal (엽록체의 전자전달과 광음향 신호에 미치는 Simetryne의 영향)

  • 김현식
    • Journal of Plant Biology
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    • v.31 no.3
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    • pp.205-215
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    • 1988
  • The effects of simetryne on light induced electron transport and phosphorylation in isolated spinach (Spinacia oleracea L.) chloroplasts were investigated in comparison with sencor and DCMU. Simetryne, like sencor and DCMU, completely, inhibited PSII electron transport and phosphoryltion with 10-6 M treatment but did not inhibit PSI electron transport. Interference with the electron transport pathway was evidenced by the greater sensitivity of oxygen evolution and uptake than phosphorylation. The following order of decreasing inhibitory effectiveness was exihibited; DCMU>simetryne>sencor. The photoacoustic technique was also used to monitor the relative photosynthetic activity in the leaves treated with the herbicides (simetryne, sencor or DCMU) in vivo and in vitro. Photoacoustic measurements on intact leaves provide quantitative information on two related aspects of the photosynthetic process, namely, photochemical energy storage and oxygen evolution. The relative photoacoustic signal of leaves treated with the herbicides showed low level in 21 Hz, but high level in 380 Hz and on isolated chloroplasts (both 21 Hz and 380 Hz) in comparison with that of the untreated leaves. These results suggest that some of photochemical energy is converted into the heat owing to the inhibition of electorn transport pathway by the herbicides.

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Influence of Respiration on Photosynthetic Electron Transport in psaB Mutants from Cyanobacterium Synechocystis sp. PCC6803 (Cyanobacterium Synechocystis sp.PCC6803 psaB 돌연변이주의 광합성 전자전달에 미치는 호흡의 영향)

  • 윤병철;장남기
    • Asian Journal of Turfgrass Science
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    • v.11 no.1
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    • pp.59-72
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    • 1997
  • The influence of respiration on photosythetic electron transport were investigated in the Wid type and psaB mutants from Syneehocystis sp. PCC6803. The amount of glucose uptake in the wild type was proportional to the glucose concentration added in wild type and less than that of psaB mutants in the dark. It was suggested that psaB mutants more depend on the glucose than the wild type. It was investigated how the activities of isocitrate dehydrogenase(IDH) and glucose-6-phos-phate dehydrogenase(G6PDH) were changed. The activities of IDH were very low. While, the ac-tivities of G6PDH were much higher than that of IDH. These results agree to the reports that ex-ogenous glucose was dismilated aerobically via Oxidative Pentose Phosphate Pathway in heterotrophic cyanobacteria. PsaB mutants showed high G6PDH activity in the presence of glucose as well as in the dark and high respiratory activities especially in the dark. It was also investigated how photosynthetic electron transport activities were changed. PsaB mutants showed higher photosynthetic electron tranasport activities than wild type in the presence of glucose as well as in the dark. In the results, it was proposed that photosynthetic electron transport between PS I and PS U was complemented by respiratory electron transport through the NADPH generated by Dxidative Pentose Phophate Pathway in psaB mutant from Synechocystis sp. PCC6803. Key words: Photosynthetic electron transport, Respiration, Synechoystis sp. PCC6803, psaB mutant, Glucose uptake, IDH, G6PDH, Respiratory electron transport activity.

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Nuclides Transport Analysis and Dose Calculation Using Dynamic Model for Rice Ingestion Pathway (쌀 섭취경로에서 동적모델을 사용한 장반감기핵종의 거동해석 및 내부피폭 선량계산)

  • Lee, Chang-Woo;Choi, Yong-Ho;Hwang, Won-Tae;Lee, Jeong-Ho
    • Journal of Radiation Protection and Research
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    • v.17 no.2
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    • pp.15-23
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    • 1992
  • Transport behaviors of Cs-137 and Sr-90 were analyzed and ingestion doses were calculated using dynamic model for rice field-rice-man pathway. Cs-137 binding strongly to soil remain longer in rice field than Sr-90. Foliar deposition on rice plant during growing period is the main contamination mechanism.

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Numerical Study of Contaminant Pathway based on Generic-scenarios and Contaminant-based Scenarios of Vadose Zone (범용 시나리오 및 오염물질 시나리오에 기반한 불포화대 오염물질 경로에 대한 수치모의 연구)

  • Chang, Sun Woo;Kim, Min-Gyu;Chung, Il-Moon
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.39 no.6
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    • pp.751-758
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    • 2019
  • This study tested various assumptions that simplified the configuration of the numerical model for unsaturated zone's contaminant transport to simulate the pathway to exposed point. This study investigated the contaminant migration through in the pollutant exposure pathway of vadoze zone for risk assessment of the contaminated site. For the purpose, generic scenarios as well as contaminant-based scenarios were simulated using the numerical code for transport of the contaminant in the pathway. The finite-difference one-dimensional transport with adsorption and biodegradation were considered, and it also assumed that the initial concentration was also depleted over time. The results of the generic-scenario show that as the groundwater infiltration rate decreases, the longer the path from the source to the groundwater level, the lower the concentration at the point of inflow into the groundwater level. In particular, in the case of high biodegradation rate and rapid depletion of pollutant sources, statistically outliers were found in the simulated results and generic scenarios was good at prediction.

Effects of Adipokine Retnla on the Regulation of High-Density Lipoprotein Metabolism

  • Lee, Mi-Ran
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.12
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    • pp.139-145
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    • 2016
  • In this paper, we propose to evaluate the effect of Resistin-like molecule alpha (Retnla) on the expression of transporters involved in modulating concentrations of peripheral cholesterol and plasma high-density lipoprotein (HDL) cholesterol. High levels of blood cholesterol are a well-recognized risk factor for atherosclerosis and are eliminated via the process of reverse cholesterol transport (RCT). We recently showed that Retnla ameliorates hypercholesterolemia and atherosclerosis by increasing biliary cholesterol secretion, the final step of the process, in low-density lipoprotein receptor-deficient mice. However, the role of Retnla in HDL-mediated cholesterol efflux, initial step of RCT pathway, is not yet clear. To identify cholesterol transport genes regulated by Retnla, we performed an extensive microarray-based gene expression screen using livers from Retnla-overexpressing (Tg) mice and control animals. The most significant change in Retnla-Tg mice was an upregulation of ATP-binding cassette sub-family G member 4 (Abcg4) transport and was validated using quantitative RT-PCR. The validated gene was also induced by treatment of purified Retnla protein in RAW 264.7 cells incubated with acetylated low-density lipoprotein and Hepa1c1c7 cells. Taken together, these results indicates that Retnla might also accelerate initial step of RCT pathway, suggesting therapeutic value of Retnla in the treatment of hypercholesterolemia and atherosclerosis.

Radionuclides Transport from the Hypothetical Disposal Facility in the KURT Field Condition on the Time Domain (KURT 부지 환경에 위치한 가상의 처분 시설에서 누출되는 방사성 핵종의 이동을 Time Domain에서 해석하는 방법에 관한 연구)

  • Hwang, Youngtaek;Ko, Nak-Youl;Choi, Jong Won;Jo, Seong-Seock
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.10 no.4
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    • pp.295-303
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    • 2012
  • Based on the data observed and analyzed on a groundwater flow system in the KURT (KAERI Underground Research Tunnel) site, the transport of radionuclides, which were assumed to be released at the supposed position, was calculated on the time-domain. A groundwater pathway from the release position to the surface was identified by simulating the groundwater flow model with the hydrogeological characteristics measured from the field tests in the KURT site. The elapsed time when the radionuclides moved through the pathway is evaluated using TDRW (Time Domain Random Walk) method for simulating the transport on the time-domain. Some retention mechanisms, such as radioactive decay, equilibrium sorption, and matrix diffusion, as well as the advection-dispersion were selected as the factors to influence on the elapsed time. From the simulation results, the effects of the sorption and matrix diffusion, determined by the properties of the radionuclides and underground media, on the transport of the radionuclides were analyzed and a decay chain of the radionuclides was also examined. The radionuclide ratio of the mass discharge into the surface environment to the mass released from the supposed repository did not exceed $10^{-3}$, and it decreased when the matrix diffusion were considered. The method used in this study could be used in preparing the data on radionuclide transport for a safety assessment of a geological disposal facility because the method could evaluate the travel time of the radionuclides considering the transport retention mechanism.