In agricultural catchments where groundwater (GW) base flow discharge contributes substantially towards stream flow, the information linking GW inflow/outflow with contaminant import/export is scarce. However, this in...In agricultural catchments where groundwater (GW) base flow discharge contributes substantially towards stream flow, the information linking GW inflow/outflow with contaminant import/export is scarce. However, this information is essential to address aquatic ecosystem health hazard/risk associated with nitrate export and subsequent loading in sensitive surface water bodies (SWB). The objectives of this study were to assess the temporal dynamics of (i) rain water inflow/outflow behaviour in three agricultural catchments in the humid tropics of far-northeast Queensland of Australia, (ii) solute import via inflow and subsequent export in outflow, and (iii) the association between GW inflow/outflow and solute import/export. Approximately 71% of the average seasonal rainfall percolated (inflow) into the porous basaltic regolith of the Johnstone River Catchment (JRC) compared with 44% into the alluvial regolith in the Mulgrave River Catchment (MRC) and 29% into the metamorphic regolith in the Tully River Catchment (TRC), respectively. The outflows from the basaltic, alluvial, and metamorphic regoliths were 56%, 36%, and 55% of the inflows, respectively. The cumulative nitrate import per season was 25 k/ha in the JRC compared with 11 kg/ha in MRC and 34 kg/ha in TRC. The corresponding exports were 24 kg/ha, 8 kg/ha 26 kg/ha in JRC, MRC, and TRC, respectively. The total dissolved solute (TDS) exports were 82%, 77%, 75%, of the corresponding imports in JRC, MRC, and TRC, respectively. Simple correlations indicated that nitrate export was positively correlated with the outflow in each one of the regolith and similar trends were observed between inflow and import. The import/export mass balance for nitrate shows that 73% to 96% of the imports were exported during the same rainy season, suggesting the potential for nitrate associated ecosystem health hazard/risk in sensitive SWB receiving the outflows.展开更多
In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,es...In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low stresses.Pore pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the filter.The role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe installation.Results show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early measurements.Both inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading condition.Various sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests performed.Data are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.展开更多
Prediction of water inflow into a tunnel is a crucial prerequisite for the waterproof and drainage design of mountain tunnels in water-rich areas.Based on the proposed Baiyun Mountain Tunnel project in Guangzhou,a num...Prediction of water inflow into a tunnel is a crucial prerequisite for the waterproof and drainage design of mountain tunnels in water-rich areas.Based on the proposed Baiyun Mountain Tunnel project in Guangzhou,a numerical percolation model of random fractured rock of a tunnel underpassing a water reservoir is established to study the seepage characteristics of surrounding rock,the law of water inflow,and the change of lining water pressure,considering the local artificial boundary conditions for seepage in large rock mass,.In addition,the influences of rock permeability,fracture aperture,grouting circle thickness,and penetration are analyzed.The results show that:(1)Only fractures with aperture wider than 0.1 mm can play a significant role in water conduction in rocks with the permeability lower than 10^(-11)m^(2);(2)The greater the permeability difference between the fractures and rocks,the more remarkable the effects of fractures on the surrounding rock seepage field and cavern water inflow;(3)The sensitivity of grouting waterproof function to grouting circle thickness,grouting ring penetration,and rock permeability is significantly higher than that of tunnel buried depth and fracture aperture;(4)The lining water head is much more sensitive to the grouting circle thickness and penetration than to the tunnel buried depth;(5)With the grouting range enlarging,the impact of grouting circle permeability on the precipitation pressure role of the grouting ring increases;(6)For the interesting tunnel designed to be built at the depth of 70 m,the grouting circle with the thickness of 0.5 m and permeability of 10-^(14)m^(2)is recommended.展开更多
This study employs the self-organizing map method to investigate the upper-tropospheric outflow patterns of tropical cyclones(TCs)over the western North Pacific from 1979 to 2019,using the 200 hPa horizontal wind fiel...This study employs the self-organizing map method to investigate the upper-tropospheric outflow patterns of tropical cyclones(TCs)over the western North Pacific from 1979 to 2019,using the 200 hPa horizontal wind fields from the ERA5 reanalysis datasets.According to the number and orientation of TC outflow channels,as well as the wind speed,the outflow patterns are classified into five categories:southwestward single-channel pattern S1(26.1%);northwestward single-channel pattern S2(23.6%);northeastward single-channel pattern S3(23.6%);double-channel outflow pattern D(20.8%);and high latitude outflow pattern H(6.0%).Composite analysis shows that the orientations of the TC outflow channels are aligned with the direction of the environmental vertical wind shear and closely related to the distribution of the environmental inertial instability,upper-level divergence,and inner-core convective activities.TC intensity and intensity changes for different outflow patterns are also significantly different.Patterns S1 and S2 usually appear in the development phase and are thus prone to TC intensification,while patterns S3 and H usually occur in the weakening phase and are thus prone to TC weakening.The double-channel pattern(D)has the largest mean intensity and accounts for more than 60%of super-typhoon samples.展开更多
BACKGROUND Hepatic venous outflow obstruction(HVOO)is a rare but serious complication of liver transplantation,particularly in piggyback liver transplantation techniques where the inferior vena cava(IVC)is preserved.C...BACKGROUND Hepatic venous outflow obstruction(HVOO)is a rare but serious complication of liver transplantation,particularly in piggyback liver transplantation techniques where the inferior vena cava(IVC)is preserved.CASE SUMMARY A transplanted liver patient underwent retransplantation due to hepatic artery thrombosis and subsequently developed HVOO caused by graft compression of the IVC.A novel approach using a retrohepatic tissue expander effectively relieved the IVC compression,restored venous outflow,and stabilized hemodynamics.We discuss this case in the context of current treatment options and advances in HVOO management,from endovascular interventions such as balloon dilation and stenting to innovative surgical solutions such as graft repositioning and retrohepatic implants.CONCLUSION This case shows how important personalized treatments are for managing HVOO and how tissue expanders can be an adjustable and less invasive option.展开更多
The performance of hepatic surgery without a parenchyma-sparing strategy carries significant risks for patient survival because of the not negligible occurrence of postoperative liver failure.The key factor of modern ...The performance of hepatic surgery without a parenchyma-sparing strategy carries significant risks for patient survival because of the not negligible occurrence of postoperative liver failure.The key factor of modern hepatic surgery is the use of the intraoperative ultrasound(IOUS),not only to stage the disease,but more importantly to guide resection with the specific aim to maximize the sparing of the functional parenchyma.Whether in patients with hepatocellular carcinoma and underlying liver cirrhosis,or in patients with colorectal liver metastasis,IOUS allows the performance of the so-called "radical but conservative surgery",which is the pivotal factor to offer a chance of cure to an increasing proportion of patients,who until few years ago were considered only for palliative care.Using some new IOUS-guided surgical maneuvers,which are based on the liver inflow and outflow modulations,more precise anatomically subsegmental-and segmentaloriented resections can be effectively performed.The present work describes the rationale and the surgical technique for a precise tailoring of the area of hepatic resection using the most recent attainments in IOUS.Such important technical achievements should be a fundamental part of the surgical armamentarium of the modern liver surgeon.展开更多
The floating photovoltaic membrane prototype developed by Ocean Sun was selected as a reference object,and a 1∶40 scale laboratory model was designed and produced to further explore the impact of inflow conditions on...The floating photovoltaic membrane prototype developed by Ocean Sun was selected as a reference object,and a 1∶40 scale laboratory model was designed and produced to further explore the impact of inflow conditions on the hydrodynamic properties of the membrane structure.By conducting free attenuation tests,results showed that the inflow has only a slight effect on the natural frequencies of the heave,pitch,and surge of the membrane structure.This finding shows that the dynamic properties of the membrane structure remain essentially stable under different inflow conditions.The results of further regular and irregular wave hydrodynamic experiments show that,compared with the control group,the response of the membrane structure under inflow conditions in terms of heave,pitch,surge,and heave acceleration motions is relatively gentle,whereas the response of the membrane structure to the mooring force is strong.Especially when the waves are irregular,the inflow conditions have a more significant impact on the membrane structure,which may lead to more complex response changes in the structure.Therefore,in the actual engineering design process,the impact of inflow conditions on the behavior of the membrane structure must be fully considered,and appropriate engineering measures must be taken to ensure the safety and stability of the structure.展开更多
According to the boundary condition with the zero,negative,or positive velocity,the initial boundary problem for compressible multi-phase flow with the Dirichlet-type boundary condition can be classified into three ca...According to the boundary condition with the zero,negative,or positive velocity,the initial boundary problem for compressible multi-phase flow with the Dirichlet-type boundary condition can be classified into three cases:impermeable problem,inflow problem,or outflow problem.In this paper,we review the recent progress on the existence and nonlinear stability of the stationary solution to the outflow/inflow problems for viscous multi-phase flow.展开更多
Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often cau...Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often causing significant groundwater inflow during drilling due to the limitations of empirical and analytical methods. This study aims to identify the geological factors influencing water flow into the tunnel. High-flow zones' geological features have been identified and examined for this purpose. According to the geological complexity of the Nowsud tunnel, presence of different formations with different permeability and karstification have led to a high volume of underground inflow water (up to 4700 L/s) to the tunnel. The Nowsud tunnel faces significant geological and hydrogeological challenges due to its passage through the Ilam formation's LI2 unit, characterized by dissolution channels, faults, and fractures. The highest inflow rate (4700 L/s) occurred in the Hz-9 zone within the Zimkan anticline. The relationship between geological features and groundwater inflow indicates that anticlines are more susceptible to inflow than synclines. Additionally, different types of faults exhibit varying hydraulic effects, with strike-slip faults having the most significant impact on groundwater inflow, thrust faults conducting less water into the tunnel, and inflow through normal faults being negligible compared to the other two types of faults. The novelty of this paper lies in its detailed analysis of geological features influencing groundwater inflow into the Nowsud tunnel, providing empirical data on high-flow zones and differentiating the hydraulic effects of various fault types, which enhances the understanding and prediction of groundwater inflow in underground constructions.展开更多
This study investigated the effects of upper-level descending inflow(ULDI)associated with inner-eyewall convection on the formation of the moat in tropical cyclones(TCs)with secondary eyewall formation(SEF).In our num...This study investigated the effects of upper-level descending inflow(ULDI)associated with inner-eyewall convection on the formation of the moat in tropical cyclones(TCs)with secondary eyewall formation(SEF).In our numerical experiments,a clear moat with SEF occurred in TCs with a significant ULDI,while no SEF occurred in TCs without a significant ULDI.The eyewall convection developed more vigorously in the control run.A ULDI occurred outside the inner-eyewall convection,where it was symmetrically unstable.The ULDI was initially triggered by the diabatic warming released by the inner eyewall and later enhanced by the cooling below the anvil cloud.The ULDI penetrated the outer edge of the inner eyewall with relatively dry air and prevented excessive solid-phase hydrometeors from being advected further outward.It produced extensive sublimation cooling of falling hydrometeors between the eyewall and the outer convection.The sublimation cooling resulted in negative buoyancy and further induced strong subsidence between the eyewall and the outer convection.As a result,a clear moat was generated.Development of the moat in the ongoing SEF prevented the outer rainband from moving farther inward,helping the outer rainband to symmetrize into an outer eyewall.In the sensitivity experiment,no significant ULDI formed since the eyewall convection was weaker,and the eyewall anvil developed relatively lower,meaning the formation of a moat and thus an outer eyewall was less likely.This study suggests that a better-represented simulation of inner-eyewall convective structures and distribution of the solid-phase hydrometeors is important to the prediction of SEF.展开更多
To help the clinical screening and diagnosis of abdominal aortic aneurysm(AAA), we evaluated the effect of inflow angle (IA) and outflow bifurcation angle(BA) on the distribution of blood flow and wall shear stress(WS...To help the clinical screening and diagnosis of abdominal aortic aneurysm(AAA), we evaluated the effect of inflow angle (IA) and outflow bifurcation angle(BA) on the distribution of blood flow and wall shear stress(WSS) in an idealized AAA model. A 2D incompressible Newtonian flow is assumed and the computational simulation is performed using finite volume method. The results showed that the largest WSS often located at the proximal and the distal end of the AAA. An increase in IA resulted in an increase in maximum WSS. We also found that WSS was maximal when BA was 90°. IA and BA are two important geometrical factors, they may help AAA risk assessment along with the commonly used AAA diameter.展开更多
BACKGROUND Postoperative complications like remnant hepatic vein(HV)outflow block and liver torsion can occur after right hepatectomy.Hepatic falciform ligament fixation is typically used to prevent liver torsion.We r...BACKGROUND Postoperative complications like remnant hepatic vein(HV)outflow block and liver torsion can occur after right hepatectomy.Hepatic falciform ligament fixation is typically used to prevent liver torsion.We report a novel procedure to manage outflow block.CASE SUMMARY An 80-year-old man developed HV outflow block after remnant right hepatectomy,despite liver fixation and intraoperative HV flow check.He had a history of cholangiocellular carcinoma and had undergone posterior segmentectomy and choledojejunostomy.The falciform ligament fixation was inadequate to maintain liver position.Emergency surgery was performed,using an omental flap and mobilized right side colon with ileocecal region to prevent liver dislocation due to intraabdominal adhesion.His postoperative course was uneventful.CONCLUSION This is the first report providing a novel surgical procedure when the falciform ligament is insufficient for remnant liver fixation.展开更多
文摘In agricultural catchments where groundwater (GW) base flow discharge contributes substantially towards stream flow, the information linking GW inflow/outflow with contaminant import/export is scarce. However, this information is essential to address aquatic ecosystem health hazard/risk associated with nitrate export and subsequent loading in sensitive surface water bodies (SWB). The objectives of this study were to assess the temporal dynamics of (i) rain water inflow/outflow behaviour in three agricultural catchments in the humid tropics of far-northeast Queensland of Australia, (ii) solute import via inflow and subsequent export in outflow, and (iii) the association between GW inflow/outflow and solute import/export. Approximately 71% of the average seasonal rainfall percolated (inflow) into the porous basaltic regolith of the Johnstone River Catchment (JRC) compared with 44% into the alluvial regolith in the Mulgrave River Catchment (MRC) and 29% into the metamorphic regolith in the Tully River Catchment (TRC), respectively. The outflows from the basaltic, alluvial, and metamorphic regoliths were 56%, 36%, and 55% of the inflows, respectively. The cumulative nitrate import per season was 25 k/ha in the JRC compared with 11 kg/ha in MRC and 34 kg/ha in TRC. The corresponding exports were 24 kg/ha, 8 kg/ha 26 kg/ha in JRC, MRC, and TRC, respectively. The total dissolved solute (TDS) exports were 82%, 77%, 75%, of the corresponding imports in JRC, MRC, and TRC, respectively. Simple correlations indicated that nitrate export was positively correlated with the outflow in each one of the regolith and similar trends were observed between inflow and import. The import/export mass balance for nitrate shows that 73% to 96% of the imports were exported during the same rainy season, suggesting the potential for nitrate associated ecosystem health hazard/risk in sensitive SWB receiving the outflows.
文摘In situ inflow and outflow permeability tests with the BAT probe at SarapuíII soft clay test site are presented.A description of the BAT permeability test is provided,discussing its advantages and shortcomings,especially in the case of very soft clays under low stresses.Pore pressures were monitored during probe installation and were found to be slightly lower than piezocone u2 pore pressures,consistent with the position of the filter.The role of filter tip saturation was investigated after the usual saturation procedure provided an unsatisfactory pore pressure response during probe installation.Results show that the vacuum saturation procedure provides adequate response during installation and increases the reliability of the coefficient of permeability determination in early measurements.Both inflow and outflow tests yielded similar results,indicating that careful execution of the test can lead to good test repeatability regardless of the loading condition.Various sequences of alternated inflow and outflow tests have yielded similar results,indicating that soil reconsolidation and filter clogging were negligible in the tests performed.Data are presented concerning the relationship between index parameters and the in situ coefficient of permeability for SarapuíII clay,which plot outside the range of existing databases.
文摘Prediction of water inflow into a tunnel is a crucial prerequisite for the waterproof and drainage design of mountain tunnels in water-rich areas.Based on the proposed Baiyun Mountain Tunnel project in Guangzhou,a numerical percolation model of random fractured rock of a tunnel underpassing a water reservoir is established to study the seepage characteristics of surrounding rock,the law of water inflow,and the change of lining water pressure,considering the local artificial boundary conditions for seepage in large rock mass,.In addition,the influences of rock permeability,fracture aperture,grouting circle thickness,and penetration are analyzed.The results show that:(1)Only fractures with aperture wider than 0.1 mm can play a significant role in water conduction in rocks with the permeability lower than 10^(-11)m^(2);(2)The greater the permeability difference between the fractures and rocks,the more remarkable the effects of fractures on the surrounding rock seepage field and cavern water inflow;(3)The sensitivity of grouting waterproof function to grouting circle thickness,grouting ring penetration,and rock permeability is significantly higher than that of tunnel buried depth and fracture aperture;(4)The lining water head is much more sensitive to the grouting circle thickness and penetration than to the tunnel buried depth;(5)With the grouting range enlarging,the impact of grouting circle permeability on the precipitation pressure role of the grouting ring increases;(6)For the interesting tunnel designed to be built at the depth of 70 m,the grouting circle with the thickness of 0.5 m and permeability of 10-^(14)m^(2)is recommended.
基金supported by the National Natural Science Foundation of China[grant numbers 42192553 and 61827091]。
文摘This study employs the self-organizing map method to investigate the upper-tropospheric outflow patterns of tropical cyclones(TCs)over the western North Pacific from 1979 to 2019,using the 200 hPa horizontal wind fields from the ERA5 reanalysis datasets.According to the number and orientation of TC outflow channels,as well as the wind speed,the outflow patterns are classified into five categories:southwestward single-channel pattern S1(26.1%);northwestward single-channel pattern S2(23.6%);northeastward single-channel pattern S3(23.6%);double-channel outflow pattern D(20.8%);and high latitude outflow pattern H(6.0%).Composite analysis shows that the orientations of the TC outflow channels are aligned with the direction of the environmental vertical wind shear and closely related to the distribution of the environmental inertial instability,upper-level divergence,and inner-core convective activities.TC intensity and intensity changes for different outflow patterns are also significantly different.Patterns S1 and S2 usually appear in the development phase and are thus prone to TC intensification,while patterns S3 and H usually occur in the weakening phase and are thus prone to TC weakening.The double-channel pattern(D)has the largest mean intensity and accounts for more than 60%of super-typhoon samples.
文摘BACKGROUND Hepatic venous outflow obstruction(HVOO)is a rare but serious complication of liver transplantation,particularly in piggyback liver transplantation techniques where the inferior vena cava(IVC)is preserved.CASE SUMMARY A transplanted liver patient underwent retransplantation due to hepatic artery thrombosis and subsequently developed HVOO caused by graft compression of the IVC.A novel approach using a retrohepatic tissue expander effectively relieved the IVC compression,restored venous outflow,and stabilized hemodynamics.We discuss this case in the context of current treatment options and advances in HVOO management,from endovascular interventions such as balloon dilation and stenting to innovative surgical solutions such as graft repositioning and retrohepatic implants.CONCLUSION This case shows how important personalized treatments are for managing HVOO and how tissue expanders can be an adjustable and less invasive option.
文摘The performance of hepatic surgery without a parenchyma-sparing strategy carries significant risks for patient survival because of the not negligible occurrence of postoperative liver failure.The key factor of modern hepatic surgery is the use of the intraoperative ultrasound(IOUS),not only to stage the disease,but more importantly to guide resection with the specific aim to maximize the sparing of the functional parenchyma.Whether in patients with hepatocellular carcinoma and underlying liver cirrhosis,or in patients with colorectal liver metastasis,IOUS allows the performance of the so-called "radical but conservative surgery",which is the pivotal factor to offer a chance of cure to an increasing proportion of patients,who until few years ago were considered only for palliative care.Using some new IOUS-guided surgical maneuvers,which are based on the liver inflow and outflow modulations,more precise anatomically subsegmental-and segmentaloriented resections can be effectively performed.The present work describes the rationale and the surgical technique for a precise tailoring of the area of hepatic resection using the most recent attainments in IOUS.Such important technical achievements should be a fundamental part of the surgical armamentarium of the modern liver surgeon.
基金The National Natural Science Foundation of China(No.52171274).
文摘The floating photovoltaic membrane prototype developed by Ocean Sun was selected as a reference object,and a 1∶40 scale laboratory model was designed and produced to further explore the impact of inflow conditions on the hydrodynamic properties of the membrane structure.By conducting free attenuation tests,results showed that the inflow has only a slight effect on the natural frequencies of the heave,pitch,and surge of the membrane structure.This finding shows that the dynamic properties of the membrane structure remain essentially stable under different inflow conditions.The results of further regular and irregular wave hydrodynamic experiments show that,compared with the control group,the response of the membrane structure under inflow conditions in terms of heave,pitch,surge,and heave acceleration motions is relatively gentle,whereas the response of the membrane structure to the mooring force is strong.Especially when the waves are irregular,the inflow conditions have a more significant impact on the membrane structure,which may lead to more complex response changes in the structure.Therefore,in the actual engineering design process,the impact of inflow conditions on the behavior of the membrane structure must be fully considered,and appropriate engineering measures must be taken to ensure the safety and stability of the structure.
基金supported by the National Natural Science Foundation of China(nos.11931010,11871047)the key research project of Academy for Multidisciplinary Studies,Capital Normal University,and by the Capacity Building for Sci-Tech Innovation-Fundamental Scientific Research Funds(no.007/20530290068).
文摘According to the boundary condition with the zero,negative,or positive velocity,the initial boundary problem for compressible multi-phase flow with the Dirichlet-type boundary condition can be classified into three cases:impermeable problem,inflow problem,or outflow problem.In this paper,we review the recent progress on the existence and nonlinear stability of the stationary solution to the outflow/inflow problems for viscous multi-phase flow.
文摘Highly permeable geological structures such as dissolution channels, open fractures, and faults create environmental challenges regard to hydrological and hydrogeological aspects of underground construction, often causing significant groundwater inflow during drilling due to the limitations of empirical and analytical methods. This study aims to identify the geological factors influencing water flow into the tunnel. High-flow zones' geological features have been identified and examined for this purpose. According to the geological complexity of the Nowsud tunnel, presence of different formations with different permeability and karstification have led to a high volume of underground inflow water (up to 4700 L/s) to the tunnel. The Nowsud tunnel faces significant geological and hydrogeological challenges due to its passage through the Ilam formation's LI2 unit, characterized by dissolution channels, faults, and fractures. The highest inflow rate (4700 L/s) occurred in the Hz-9 zone within the Zimkan anticline. The relationship between geological features and groundwater inflow indicates that anticlines are more susceptible to inflow than synclines. Additionally, different types of faults exhibit varying hydraulic effects, with strike-slip faults having the most significant impact on groundwater inflow, thrust faults conducting less water into the tunnel, and inflow through normal faults being negligible compared to the other two types of faults. The novelty of this paper lies in its detailed analysis of geological features influencing groundwater inflow into the Nowsud tunnel, providing empirical data on high-flow zones and differentiating the hydraulic effects of various fault types, which enhances the understanding and prediction of groundwater inflow in underground constructions.
基金supported by the National Natural Science Foundation of China(Grant Nos.42192552,42192551,42150710531,42175016,and 42075072)the Shanghai Typhoon Research Fund(Grant No.TFJJ202207)the Basic Research Fund of CAMS(Grant No.2023Y010)。
文摘This study investigated the effects of upper-level descending inflow(ULDI)associated with inner-eyewall convection on the formation of the moat in tropical cyclones(TCs)with secondary eyewall formation(SEF).In our numerical experiments,a clear moat with SEF occurred in TCs with a significant ULDI,while no SEF occurred in TCs without a significant ULDI.The eyewall convection developed more vigorously in the control run.A ULDI occurred outside the inner-eyewall convection,where it was symmetrically unstable.The ULDI was initially triggered by the diabatic warming released by the inner eyewall and later enhanced by the cooling below the anvil cloud.The ULDI penetrated the outer edge of the inner eyewall with relatively dry air and prevented excessive solid-phase hydrometeors from being advected further outward.It produced extensive sublimation cooling of falling hydrometeors between the eyewall and the outer convection.The sublimation cooling resulted in negative buoyancy and further induced strong subsidence between the eyewall and the outer convection.As a result,a clear moat was generated.Development of the moat in the ongoing SEF prevented the outer rainband from moving farther inward,helping the outer rainband to symmetrize into an outer eyewall.In the sensitivity experiment,no significant ULDI formed since the eyewall convection was weaker,and the eyewall anvil developed relatively lower,meaning the formation of a moat and thus an outer eyewall was less likely.This study suggests that a better-represented simulation of inner-eyewall convective structures and distribution of the solid-phase hydrometeors is important to the prediction of SEF.
文摘To help the clinical screening and diagnosis of abdominal aortic aneurysm(AAA), we evaluated the effect of inflow angle (IA) and outflow bifurcation angle(BA) on the distribution of blood flow and wall shear stress(WSS) in an idealized AAA model. A 2D incompressible Newtonian flow is assumed and the computational simulation is performed using finite volume method. The results showed that the largest WSS often located at the proximal and the distal end of the AAA. An increase in IA resulted in an increase in maximum WSS. We also found that WSS was maximal when BA was 90°. IA and BA are two important geometrical factors, they may help AAA risk assessment along with the commonly used AAA diameter.
文摘BACKGROUND Postoperative complications like remnant hepatic vein(HV)outflow block and liver torsion can occur after right hepatectomy.Hepatic falciform ligament fixation is typically used to prevent liver torsion.We report a novel procedure to manage outflow block.CASE SUMMARY An 80-year-old man developed HV outflow block after remnant right hepatectomy,despite liver fixation and intraoperative HV flow check.He had a history of cholangiocellular carcinoma and had undergone posterior segmentectomy and choledojejunostomy.The falciform ligament fixation was inadequate to maintain liver position.Emergency surgery was performed,using an omental flap and mobilized right side colon with ileocecal region to prevent liver dislocation due to intraabdominal adhesion.His postoperative course was uneventful.CONCLUSION This is the first report providing a novel surgical procedure when the falciform ligament is insufficient for remnant liver fixation.
