According to the drainage problems emerging from the several torrential rainstorm in domestic coastal cities in the last two years, especially the issues that the drainage and waterlogging prevention of coastal cities...According to the drainage problems emerging from the several torrential rainstorm in domestic coastal cities in the last two years, especially the issues that the drainage and waterlogging prevention of coastal cities are susceptible to the tide level of open seas, this paper took the reconstruction of Yingping District in Xiamen, a typical coastal area, as a case study, analyzed the main waterlogging causes of the district under the influences of the average annual tide level and storm tide caused by typhoon with the application of drainage model, and came up with reasonable implementation strategies for reconstruction;besides, this paper also assessed and divided the waterlogging risks of the district under the influences of storm tide and applied engineering measures as well as non-engineering measures to prevent the urban cities from water-logging hazards. It is expected that the study would provide reference for the reconstruction of coastal cities in drainage and water-logging prevention.展开更多
Stability of the magnetic resonance (MR) contrast agent inside vascular occlusion agents is important for their localization with magnetic resonance imaging (MRI). The aim of this paper is to study the behaviour of th...Stability of the magnetic resonance (MR) contrast agent inside vascular occlusion agents is important for their localization with magnetic resonance imaging (MRI). The aim of this paper is to study the behaviour of the superparamagnetic iron oxide (SPIO) within Hepaspheres? microparticles (MP) by MRI when they are submitted to negative pressure induced by venous drainage of a tumor. Therefore, a venous drainage model was established and three parameters were taken into account according to physiologic parameters in tumors: pH, temperature and flow blood rate. Four cycles of pumping were performed with the presence of labeled Hepaspheres? with Endorem?. Several MR images of MP and perfusion liquid were taken before and after pumping. Endorem? release was determined after correction of non-uniformity intensities in MR images. Intensity variation according to spatial position, coil and MR acquisition parameters was studied. Labeled microparticles (LB*MP) appeared as black spots in MRI images whatever duration and pH. Our model demonstrates the stability of the SPIO inside the occlusion agent during time. Moreover, the proposed correction method proves the reduction of the intensity non-uniformity in MRI images.展开更多
A gas migration controlling equation was formulated based on the characteristics of the dual pore–fracture media of coal mass and in consideration of the matrix exchange between pores and fractures.A model of permeab...A gas migration controlling equation was formulated based on the characteristics of the dual pore–fracture media of coal mass and in consideration of the matrix exchange between pores and fractures.A model of permeability dynamic evolution was established by analyzing the variation in effective stress during gas drainage and the action mechanism of the effect of coal matrix desorption on porosity and fracture in the coal body.A coupling model can then be obtained to characterize gas compressibility and coal deformability under the gas–solid coupling of loading coal.In addition,a 3D model of boreholes was established and solved for gas drainage based on the relevant physical parameters of real mines.The comparison and analysis results for the law of gas migration and the evolution of coal body permeability around the boreholes before and after gas extraction between the dual media and the single-seepage field models can provide a theoretical basis for further research on the action mechanism of gas drainage.展开更多
This manuscript is an attempt to demonstrate effectiveness of nature-based solutions (NBS) and measures to reduce risk of flooding and environmental impact in urban settings. The nature-based solutions (NBS) were asse...This manuscript is an attempt to demonstrate effectiveness of nature-based solutions (NBS) and measures to reduce risk of flooding and environmental impact in urban settings. The nature-based solutions (NBS) were assessed as scenarios from experience of urban storm drainage and sewerage systems based on practices that improve urban water management through modelling using urban stormwater management model (SWMM). The model has been applied in a typical urban environment in the second city in Botswana, the City of Francistown, which has a population of more than one hundred thousand. By considering the 2-yr and 10-year storm events in a calibrated SWMM, NBS scenarios from a mix of low impact and drainage measures were considered. The considered NBS scenarios were used to determine their effectiveness in terms of reducing and controlling peak runoff, flood volumes, infiltration and evapotranspiration in the study area, which are vital in assessing the opportunity and challenge for sustainable management of water resources and associated tradeoff of investments in the urban contexts. The study demonstrates the usefulness of implementing effective measures for achieving NBS in urban context and possibility of outscaling at basin and regional levels.展开更多
BACKGROUND Since the first living donor liver transplantation(LDLT)was performed by Raia and colleagues in December 1988,LDLT has become the gold standard treatment in countries where cadaveric organ donation is not s...BACKGROUND Since the first living donor liver transplantation(LDLT)was performed by Raia and colleagues in December 1988,LDLT has become the gold standard treatment in countries where cadaveric organ donation is not sufficient.Adequate hepatic venous outflow reconstruction in LDLT is essential to prevent graft congestion and its complications including graft loss.However,this can be complex and technically demanding especially in the presence of complex variations and congenital anomalies in the graft hepatic veins.CASE SUMMARY Herein,we aimed to present two cases who underwent successful right lobe LDLT using a right lobe liver graft with rudimentary or congenital absence of the right hepatic vein and describe the utility of a common large opening drainage model in such complex cases.CONCLUSION Thanks to this venous reconstruction model,none of the patients developed postoperative complications related to venous drainage.Our experience with venous drainage reconstruction models shows that congenital variations in the hepatic venous structure of living liver donors are not absolute contraindications for LDLT.展开更多
Morpho-tectonic study plays an important role in deciphering the effects of tectonic activity in the geomorphic evolution of the drainage basins.Romushi watershed forms one of the major watersheds of the intermontane ...Morpho-tectonic study plays an important role in deciphering the effects of tectonic activity in the geomorphic evolution of the drainage basins.Romushi watershed forms one of the major watersheds of the intermontane Karewa Basin of Kashmir Valley.The Karewa sediments are characterized by glacio-fluvio-lacustrine deposits capped by the aeolian loess.The geomorphic,morphometric and lithostratigraphic studies of these cap deposits have been carried out to elucidate the effect of tectonics on the geomorphic evolution of Romushi Watershed.Geomorphic mapping was carried out using GPS measurements,DEM at 30m resolution,Topographic Position Index(TPI) model,topographic maps,LANDSAT TM Imagery and field data.Morphometric and morphotectonic analyses in GIS environment were used to calculate various geomorphic indices(Mountain Front Sinuosity Index,Bifurcation Ratio,Asymmetry Factor,River Profile,etc).These indices reveal that the tectonic uplift observed in the region due to Himalayan orogeny coupled with mass movement and aeolian deposition have dominated the landscape evolution of intermontane Karewa Basin of Kashmir throughout the Late Quaternary Period.Additional data from lithostratigraphic measurements were analyzed to understand the geomorphic evolution of intermontane Karewa Basin.The data revealed that the basin has experienced differential uplift and erosion rates from time to time in the geological past.This was corroborated by the results from the morphometric and morphotectonic analysis.展开更多
文摘According to the drainage problems emerging from the several torrential rainstorm in domestic coastal cities in the last two years, especially the issues that the drainage and waterlogging prevention of coastal cities are susceptible to the tide level of open seas, this paper took the reconstruction of Yingping District in Xiamen, a typical coastal area, as a case study, analyzed the main waterlogging causes of the district under the influences of the average annual tide level and storm tide caused by typhoon with the application of drainage model, and came up with reasonable implementation strategies for reconstruction;besides, this paper also assessed and divided the waterlogging risks of the district under the influences of storm tide and applied engineering measures as well as non-engineering measures to prevent the urban cities from water-logging hazards. It is expected that the study would provide reference for the reconstruction of coastal cities in drainage and water-logging prevention.
基金supported by the Centre of Advanced Medical Imaging at the University of Technology of Compiegne.
文摘Stability of the magnetic resonance (MR) contrast agent inside vascular occlusion agents is important for their localization with magnetic resonance imaging (MRI). The aim of this paper is to study the behaviour of the superparamagnetic iron oxide (SPIO) within Hepaspheres? microparticles (MP) by MRI when they are submitted to negative pressure induced by venous drainage of a tumor. Therefore, a venous drainage model was established and three parameters were taken into account according to physiologic parameters in tumors: pH, temperature and flow blood rate. Four cycles of pumping were performed with the presence of labeled Hepaspheres? with Endorem?. Several MR images of MP and perfusion liquid were taken before and after pumping. Endorem? release was determined after correction of non-uniformity intensities in MR images. Intensity variation according to spatial position, coil and MR acquisition parameters was studied. Labeled microparticles (LB*MP) appeared as black spots in MRI images whatever duration and pH. Our model demonstrates the stability of the SPIO inside the occlusion agent during time. Moreover, the proposed correction method proves the reduction of the intensity non-uniformity in MRI images.
基金supported by Chinese Ministry of Education (No.213022A)the National Natural Science Foundation of China (No.51574112)+4 种基金Henan Key Laboratory of Biogenic Traces and Sedimentary Minerals (No.OTMP1410)the Key Research Project of Higher Education Institution of Henan Province in 2015 (No.15A440001)the Doctor Funds of Henan Polytechnic University (No.B2015-05)the Basic and Advanced Technology Research Projects of Henan Province (No.162300410031)the Science and Technology Innovation Funds for Distinguished Young Scholar in Henan Province (No.164100510013)
文摘A gas migration controlling equation was formulated based on the characteristics of the dual pore–fracture media of coal mass and in consideration of the matrix exchange between pores and fractures.A model of permeability dynamic evolution was established by analyzing the variation in effective stress during gas drainage and the action mechanism of the effect of coal matrix desorption on porosity and fracture in the coal body.A coupling model can then be obtained to characterize gas compressibility and coal deformability under the gas–solid coupling of loading coal.In addition,a 3D model of boreholes was established and solved for gas drainage based on the relevant physical parameters of real mines.The comparison and analysis results for the law of gas migration and the evolution of coal body permeability around the boreholes before and after gas extraction between the dual media and the single-seepage field models can provide a theoretical basis for further research on the action mechanism of gas drainage.
文摘This manuscript is an attempt to demonstrate effectiveness of nature-based solutions (NBS) and measures to reduce risk of flooding and environmental impact in urban settings. The nature-based solutions (NBS) were assessed as scenarios from experience of urban storm drainage and sewerage systems based on practices that improve urban water management through modelling using urban stormwater management model (SWMM). The model has been applied in a typical urban environment in the second city in Botswana, the City of Francistown, which has a population of more than one hundred thousand. By considering the 2-yr and 10-year storm events in a calibrated SWMM, NBS scenarios from a mix of low impact and drainage measures were considered. The considered NBS scenarios were used to determine their effectiveness in terms of reducing and controlling peak runoff, flood volumes, infiltration and evapotranspiration in the study area, which are vital in assessing the opportunity and challenge for sustainable management of water resources and associated tradeoff of investments in the urban contexts. The study demonstrates the usefulness of implementing effective measures for achieving NBS in urban context and possibility of outscaling at basin and regional levels.
文摘BACKGROUND Since the first living donor liver transplantation(LDLT)was performed by Raia and colleagues in December 1988,LDLT has become the gold standard treatment in countries where cadaveric organ donation is not sufficient.Adequate hepatic venous outflow reconstruction in LDLT is essential to prevent graft congestion and its complications including graft loss.However,this can be complex and technically demanding especially in the presence of complex variations and congenital anomalies in the graft hepatic veins.CASE SUMMARY Herein,we aimed to present two cases who underwent successful right lobe LDLT using a right lobe liver graft with rudimentary or congenital absence of the right hepatic vein and describe the utility of a common large opening drainage model in such complex cases.CONCLUSION Thanks to this venous reconstruction model,none of the patients developed postoperative complications related to venous drainage.Our experience with venous drainage reconstruction models shows that congenital variations in the hepatic venous structure of living liver donors are not absolute contraindications for LDLT.
文摘Morpho-tectonic study plays an important role in deciphering the effects of tectonic activity in the geomorphic evolution of the drainage basins.Romushi watershed forms one of the major watersheds of the intermontane Karewa Basin of Kashmir Valley.The Karewa sediments are characterized by glacio-fluvio-lacustrine deposits capped by the aeolian loess.The geomorphic,morphometric and lithostratigraphic studies of these cap deposits have been carried out to elucidate the effect of tectonics on the geomorphic evolution of Romushi Watershed.Geomorphic mapping was carried out using GPS measurements,DEM at 30m resolution,Topographic Position Index(TPI) model,topographic maps,LANDSAT TM Imagery and field data.Morphometric and morphotectonic analyses in GIS environment were used to calculate various geomorphic indices(Mountain Front Sinuosity Index,Bifurcation Ratio,Asymmetry Factor,River Profile,etc).These indices reveal that the tectonic uplift observed in the region due to Himalayan orogeny coupled with mass movement and aeolian deposition have dominated the landscape evolution of intermontane Karewa Basin of Kashmir throughout the Late Quaternary Period.Additional data from lithostratigraphic measurements were analyzed to understand the geomorphic evolution of intermontane Karewa Basin.The data revealed that the basin has experienced differential uplift and erosion rates from time to time in the geological past.This was corroborated by the results from the morphometric and morphotectonic analysis.
