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Pipeline Flex血流导向装置治疗颅内动脉瘤疗效观察
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作者 谢兵 韩昊锦 +2 位作者 李锐韬 韩志安 丁明祥 《海南医学》 CAS 2024年第1期39-42,共4页
目的观察使用Pipeline Flex血流导向装置(PED)治疗颅内动脉瘤的疗效及安全性。方法回顾性分析2020年6月至2022年6月中山市人民医院使用PED治疗的25例颅内动脉瘤(共29个动脉瘤)患者的临床资料,25例患者中2例存在2个串联动脉瘤,1例有3个... 目的观察使用Pipeline Flex血流导向装置(PED)治疗颅内动脉瘤的疗效及安全性。方法回顾性分析2020年6月至2022年6月中山市人民医院使用PED治疗的25例颅内动脉瘤(共29个动脉瘤)患者的临床资料,25例患者中2例存在2个串联动脉瘤,1例有3个串联动脉瘤。29个动脉瘤分布在颈内动脉26个,大脑中动脉1个,椎基底动脉2个。术后进行临床及影像学随访,评估术后即刻动脉瘤栓塞情况和出院时患者改良Rankin评分量表(mRS),并在术后6个月及12个月时随访进行影像学检查以明确动脉瘤闭塞情况。结果25例患者均成功置入PED,其中15个动脉瘤联合弹簧圈栓塞,14个动脉瘤单独置入PED支架。术中有1例使用球囊扩张,24例经导丝微导管按摩均贴壁良好,术后临床随访中1例(4%)患者有缺血症状。术后6个月随访22个(75.9%)动脉瘤完全闭合,术后12个月随访2个(6.9%)动脉瘤影像学随访中未见闭合,27个(93.1%)动脉瘤完全闭合。结论PED治疗颅内动脉瘤短期随访安全有效,并发症较少,动脉瘤闭塞率较高。 展开更多
关键词 颅内动脉瘤 血流导向装置 治疗效果 并发症
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Pipeline血流导向装置治疗复杂性颅内动脉瘤预后的影响因素及列线图预测模型构建
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作者 张紫寅 邱冬 +9 位作者 郑萍 安阳 张涛 唐雪松 严智星 李苏雯 尹丽萍 姜永继 胡利刚 唐景峰 《介入放射学杂志》 CSCD 北大核心 2024年第9期944-949,共6页
目的 探讨Pipeline血流导向装置(PED)治疗复杂性颅内动脉瘤预后的影响因素。方法选择2021年1月至2023年4月安岳县人民医院和桂林医学院第二附属医院接诊的复杂性颅内动脉瘤患者98例。患者入组后均行PED治疗,收集可能影响复杂性颅内动脉... 目的 探讨Pipeline血流导向装置(PED)治疗复杂性颅内动脉瘤预后的影响因素。方法选择2021年1月至2023年4月安岳县人民医院和桂林医学院第二附属医院接诊的复杂性颅内动脉瘤患者98例。患者入组后均行PED治疗,收集可能影响复杂性颅内动脉瘤预后的影响因素。据改良Rankin量表得分将患者分为2组,≤2分为预后良好组,>2分为预后不良组,比较2组的临床资料。建立Nomograms模型并对模型进行验证。结果 98例患者中,10例(10.20%)出现预后不良。预后不良组与预后良好组患者年龄、高血压病史、糖尿病史、氯吡格雷抵抗、Fisher分级、动脉瘤多次破裂、动脉瘤位置、瘤体大小、瘤颈、多发及入院时Hunt-Hess分级差异均有统计学意义(P<0.05)。多因素分析结果显示,高血压病史、氯吡格雷抵抗、动脉瘤多次破裂、动脉瘤位置、多发及入院时Hunt-Hess分级为PED治疗复杂性颅内动脉瘤预后的独立性影响因素。Nomograms模型预测PED治疗复杂性颅内动脉瘤预后的AUC为0.849(95%CI:0.758~0.939)。模型组与验证组预测曲线与标准曲线基本拟合。决策曲线分析结果显示,当Nomograms模型预测PED治疗复杂性颅内动脉瘤预后不良的概率阈值为0.10~0.90时,患者的净受益率大于0。结论 PED治疗复杂性颅内动脉瘤预后不良的影响因素主要有高血压病史、氯吡格雷抵抗、动脉瘤多次破裂等,Nomograms模型可预测PED治疗复杂性颅内动脉瘤预后不良风险。 展开更多
关键词 pipeline血流导向装置 复杂性颅内动脉瘤 多因素分析 列线图预测模型
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Numerical study on local scour characteristics around submarine pipelines in the Yellow River Delta silty sandy soil under waves and currents 被引量:1
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作者 Peng Yu Ruigeng Hu +4 位作者 Jike Zhang Qi Yang Jieru Zhao Lei Cao Chenghao Zhu 《Deep Underground Science and Engineering》 2024年第2期182-196,共15页
Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil aroun... Due to their high reliability and cost-efficiency,submarine pipelines are widely used in offshore oil and gas resource engineering.Due to the interaction of waves,currents,seabed,and pipeline structures,the soil around submarine pipelines is prone to local scour,severely affecting their operational safety.With the Yellow River Delta as the research area and based on the renormalized group(RNG)k-εturbulence model and Stokes fifth-order wave theory,this study solves the Navier-Stokes(N-S)equation using the finite difference method.The volume of fluid(VOF)method is used to describe the fluid-free surface,and a threedimensional numerical model of currents and waves-submarine pipeline-silty sandy seabed is established.The rationality of the numerical model is verified using a self-built waveflow flume.On this basis,in this study,the local scour development and characteristics of submarine pipelines in the Yellow River Delta silty sandy seabed in the prototype environment are explored and the influence of the presence of pipelines on hydrodynamic features such as surrounding flow field,shear stress,and turbulence intensity is analyzed.The results indicate that(1)local scour around submarine pipelines can be divided into three stages:rapid scour,slow scour,and stable scour.The maximum scour depth occurs directly below the pipeline,and the shape of the scour pits is asymmetric.(2)As the water depth decreases and the pipeline suspension height increases,the scour becomes more intense.(3)When currents go through a pipeline,a clear stagnation point is formed in front of the pipeline,and the flow velocity is positively correlated with the depth of scour.This study can provide a valuable reference for the protection of submarine pipelines in this area. 展开更多
关键词 local scour numerical simulation submarine pipelines Yellow River Delta
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Analysis of faulting destruction and water supply pipeline damage from the first mainshock of the February 6,2023 Türkiye earthquake doublet 被引量:1
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作者 Xiaoqing Fan Libao Zhang +2 位作者 Juke Wang Yefei Ren Aiwen Liu 《Earthquake Science》 2024年第1期78-90,共13页
In 2023,two consecutive earthquakes exceeding a magnitude of 7 occurred in Türkiye,causing severe casualties and economic losses.The damage to critical urban infrastructure and building structures,including highw... In 2023,two consecutive earthquakes exceeding a magnitude of 7 occurred in Türkiye,causing severe casualties and economic losses.The damage to critical urban infrastructure and building structures,including highways,railroads,and water supply pipelines,was particularly severe in areas where these structures intersected the seismogenic fault.Critical infrastructure projects that traverse active faults are susceptible to the influence of fault movement,pulse velocity,and ground motions.In this study,we used a unique approach to analyze the acceleration records obtained from the seismic station array(9 strong ground motion stations)located along the East Anatolian Fault(the seismogenic fault of the MW7.8 mainshock of the 2023 Türkiye earthquake doublet).The acceleration records were filtered and integrated to obtain the velocity and displacement time histories.We used the results of an on-site investigation,jointly conducted by China Earthquake Administration and Türkiye’s AFAD,to analyze the distribution of PGA,PGV,and PGD recorded by the strong motion array of the East Anatolian Fault.We found that the maximum horizontal PGA in this earthquake was 3.0 g,and the maximum co-seismic surface displacement caused by the East Anatolian Fault rupture was 6.50 m.As the fault rupture propagated southwest,the velocity pulse caused by the directional effect of the rupture increased gradually,with the maximum PGA reaching 162.3 cm/s.We also discussed the seismic safety of critical infrastructure projects traversing active faults,using two case studies of water supply pipelines in Türkiye that were damaged by earthquakes.We used a three-dimensional finite element model of the PE(polyethylene)water pipeline at the Islahiye State Hospital and fault displacement observations obtained through on-site investigation to analyze pipeline failure mechanisms.We further investigated the effect of the fault-crossing angle on seismic safety of a pipeline,based on our analysis and the failure performance of the large-diameter Thames Water pipeline during the 1999 Kocaeli earthquake.The seismic method of buried pipelines crossing the fault was summarized. 展开更多
关键词 Türkiye earthquake fault displacement near-fault ground motion velocity pulse water supply pipeline
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Towards adaptable synchrotron image restoration pipeline
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作者 Chun Li Xiao-Xue Bi +6 位作者 Yu-Jun Zhang Zhen Zhang Li-Wen Wang Jian Zhuang Dong-Liang Chen Yu-Hui Dong Yi Zhang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2024年第10期4-16,共13页
Synchrotron microscopic data commonly suffer from poor image quality with degraded resolution incurred by instrumentation defects or experimental conditions.Image restoration methods are often applied to recover the r... Synchrotron microscopic data commonly suffer from poor image quality with degraded resolution incurred by instrumentation defects or experimental conditions.Image restoration methods are often applied to recover the reduced resolution,providing improved image details that can greatly facilitate scientific discovery.Among these methods,deconvolution techniques are straightforward,yet either require known prior information or struggle to tackle large experimental data.Deep learning(DL)-based super-resolution(SR)methods handle large data well,however data scarcity and model generalizability are problematic.In addition,current image restoration methods are mostly offline and inefficient for many beamlines where high data volumes and data complexity issues are encountered.To overcome these limitations,an online image-restoration pipeline that adaptably selects suitable algorithms and models from a method repertoire is promising.In this study,using both deconvolution and pretrained DL-based SR models,we show that different restoration efficacies can be achieved on different types of synchrotron experimental data.We describe the necessity,feasibility,and significance of constructing such an image-restoration pipeline for future synchrotron experiments. 展开更多
关键词 SYNCHROTRON DECONVOLUTION Deep learning SUPER-RESOLUTION pipeline
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Experimental and numerical simulation study on the erosion behavior of the elbow of gathering pipeline in shale gas field
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作者 En-Bin Liu Shen Huang +3 位作者 Ding-Chao Tian Lai-Min Shi Shan-Bi Peng He Zheng 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1257-1274,共18页
During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow... During the production period of shale gas, proppant particles and rock debris are produced together,which will seriously erode the elbows of gathering pipelines. In response to this problem, this paper takes the elbow of the gathering pipeline in the Changning Shale Gas Field as an example to test the erosion rate and material removal mechanism of the test piece at different angles of the elbow through experiments and compares the four erosion models with the experimental results. Through analysis, it is found that the best prediction model for quartz sand-carbon steel erosion is the Oka model. Based on the Oka model, FLUENT software was used to simulate and analyze the law of erosion of the elbow of the gas gathering pipeline under different gas flow velocities, gas gathering pressure, particle size, length of L1,and bending directions of the elbow. And a spiral pipeline structure is proposed to reduce the erosion rate of the elbow under the same working conditions. The results show that this structure can reduce erosion by 34%. 展开更多
关键词 Shale gas Gas gathering pipeline ELBOW EROSION CFD
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New insights into the deposition of natural gas hydrate on pipeline surfaces:A molecular dynamics simulation study
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作者 Jun Zhang Hai-Qiang Fu +7 位作者 Mu-Zhi Guo Zhao Wang Li-Wen Li Qi Yin You-Guo Yan Wei Wei Wei-Feng Han Jie Zhong 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期694-704,共11页
Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent N... Natural gas hydrate(NGH)can cause pipeline blockages during the transportation of oil and gas under high pressures and low temperatures.Reducing hydrate adhesion on pipelines is viewed as an efficient way to prevent NGH blockages.Previous studies suggested the water film can greatly increase hydrate adhesion in gas-dominant system.Herein,by performing the molecular dynamics simulations,we find in water-dominant system,the water film plays different roles in hydrate deposition on Fe and its corrosion surfaces.Specifically,due to the strong affinity of water on Fe surface,the deposited hydrate cannot convert the adsorbed water into hydrate,thus,a water film exists.As water affinities decrease(Fe>Fe_(2)O_(3)>FeO>Fe_(3)O_(4)),adsorbed water would convert to amorphous hydrate on Fe_(2)O_(3)and form the ordered hydrate on FeO and Fe_(3)O_(4)after hydrate deposition.While absorbed water film converts to amorphous or to hydrate,the adhesion strength of hydrate continuously increases(Fe<Fe_(2)O_(3)<FeO<Fe_(3)O_(4)).This is because the detachment of deposited hydrate prefers to occur at soft region of liquid layer,the process of which becomes harder as liquid layer vanishes.As a result,contrary to gas-dominant system,the water film plays the weakening roles on hydrate adhesion in water-dominant system.Overall,our results can help to better understand the hydrate deposition mechanisms on Fe and its corrosion surfaces and suggest hydrate deposition can be adjusted by changing water affinities on pipeline surfaces. 展开更多
关键词 DEPOSITION Natural gas hydrate pipelines Water affinity Adhesion strength
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Pipeline thickness estimation using the dispersion of higher-order SH guided waves
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作者 代政辰 刘金霞 +3 位作者 龙云飞 张建海 Tribikram Kundu 崔志文 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期389-396,共8页
Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thi... Thickness measurement plays an important role in the monitoring of pipeline corrosion damage. However, the requirement for prior knowledge of the shear wave velocity in the pipeline material for popular ultrasonic thickness measurement limits its widespread application. This paper proposes a method that utilizes cylindrical shear horizontal(SH) guided waves to estimate pipeline thickness without prior knowledge of shear wave velocity. The inversion formulas are derived from the dispersion of higher-order modes with the high-frequency approximation. The waveform of the example problems is simulated using the real-axis integral method. The data points on the dispersion curves are processed in the frequency domain using the wave-number method. These extracted data are then substituted into the derived formulas. The results verify that employing higher-order SH guided waves for the evaluation of thickness and shear wave velocity yields less than1% error. This method can be applied to both metallic and non-metallic pipelines, thus opening new possibilities for health monitoring of pipeline structures. 展开更多
关键词 pipeline wall thickness higher-order modes SH guided waves DISPERSION
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Behavior of transporting pipeline sections without and with hydrogen exposure based on full-scale tests
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作者 Nóra Nagy János Lukács 《China Welding》 CAS 2024年第3期14-24,共11页
Pipeline transport of hydrogen is one of today’s economic and environmental challenges.In order to find safe and reliable application of both existing gas and build new pipelines,it is essential to carry out tests on... Pipeline transport of hydrogen is one of today’s economic and environmental challenges.In order to find safe and reliable application of both existing gas and build new pipelines,it is essential to carry out tests on full-scale pipeline section,including the potentially more dangerous places than the main pipe,the girth welds.For the investigations,pipeline sections of P355NH steel with girth welds were prepared and exposed to pure hydrogen at twice the maximum allowable operating pressure for 41 days.Subsequently,full-scale burst tests were carried out and specimens were cut and prepared from the typical locations of the failed pipeline sections for mechanical,and macro-and microstructural investigations.The results obtained were evaluated and compared with data from previous full-scale tests on pipeline sections without hydrogen exposure.The results showed differences in the behavior of pipeline sections loaded in different ways,with different characteristics of the materials and the welded joints,both in the cases without hydrogen exposure and in the cases exposed to hydrogen. 展开更多
关键词 gas transporting pipeline full-scale pipeline test complex loading condition hydrogen exposure safety factor
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Experimental and Finite Element Analysis of Corroded High-Pressure Pipeline Repaired by Laminated Composite
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作者 Seyed Mohammad Reza Abtahi Saeid Ansari Sadrabadi +4 位作者 Gholam Hosein Rahimi Gaurav Singh Hamid Abyar Daniele Amato Luigi Federico 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第8期1783-1806,共24页
Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necess... Repairs of corroded high-pressure pipelines are essential for fluids transportation under high pressure.One of the methods used in their repairs is the use of layered composites.The composite used must have the necessary strength.Therefore,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME B31.G.In addition,the experimental tests are replicated numerically using the finite element method.Setting the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high pressure.The direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the defect.Composite reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed. 展开更多
关键词 High-pressure pipeline composite repair ASME PCC-2 ISO 24817
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Bending Failure Mode and Prediction Method of the Compressive Strain Capacity of A Submarine Pipeline with Dent Defects
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作者 HOU Fu-heng JIA Lu-sheng +3 位作者 CHEN Yan-fei ZHANG Qi ZHONG Rong-feng WANG Chun-sha 《China Ocean Engineering》 SCIE EI CSCD 2024年第4期636-647,共12页
A dent is a common type of defects for submarine pipeline.For submarine pipelines,high hydrostatic pressure and internal pressure are the main loads.Once pipelines bend due to complex subsea conditions,the compression... A dent is a common type of defects for submarine pipeline.For submarine pipelines,high hydrostatic pressure and internal pressure are the main loads.Once pipelines bend due to complex subsea conditions,the compression strain capacity may be exceeded.Research into the local buckling failure and accurate prediction of the compressive strain capacity are important.A finite element model of a pipeline with a dent is established.Local buckling failure under a bending moment is investigated,and the compressive strain capacity is calculated.The effects of different parameters on pipeline local buckling are analyzed.The results show that the dent depth,external pressure and internal pressure lead to different local buckling failure modes of the pipeline.A higher internal pressure indicates a larger compressive strain capacity,and the opposite is true for external pressure.When the ratio of external pressure to collapse pressure of intact pipeline is greater than 0.1,the deeper the dent,the greater the compressive strain capacity of the pipeline.And as the ratio is less than 0.1,the opposite is true.On the basis of these results,a regression equation for predicting the compressive strain capacity of a dented submarine pipeline is proposed,which can be referred to during the integrity assessment of a submarine pipeline. 展开更多
关键词 submarine pipeline dent defect bending load local buckling compressive strain capacity
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Sacrificial piles as a countermeasure against local scour around underwater pipelines
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作者 Forough Raeisi Seyed Mohammad Ali Zomorodiann +1 位作者 Masih Zolghadr Hazi Mohammad Azamathulla 《Water Science and Engineering》 EI CAS CSCD 2024年第2期187-196,共10页
Local scour around pipelines crossing rivers or in marine environments is a significant concern.It can lead to failure of the pipelines resulting in environmental side effects and economic losses.This study developed ... Local scour around pipelines crossing rivers or in marine environments is a significant concern.It can lead to failure of the pipelines resulting in environmental side effects and economic losses.This study developed an experimental method to reduce local scour around pipelines with a steady flow of clear water by installing cylindrical and cubical sacrificial piles.Three sizes of sacrificial piles were examined in a linear arrangement.Sacrificial piles were installed on the upstream side of the pipeline at three distances.Maximum scour depth reduction rates below the pipeline were computed.The results showed that sacrificial piles could protect a pipeline from local scour.A portion of scoured sediment around the sacrificial piles was deposited beneath the pipeline.This sediment accumulation reduced the scour depth beneath the pipeline.Analysis of the experimental results demonstrated that the size of piles(d),the spacing between piles,and the distance between the pipe and piles(Xp)were the variables that reduced the maximum scour beneath the pipeline with a diameter of D.For the piles with d=0.40D and 0.64D,X_(p)=4OD was the optimal distance to install a group of piles,and cubical piles could mitigate scour more effectively than cylindrical piles under similar conditions.For the piles with d=D,the greatest reduction in scour depth was achieved at X_(p)=50D with any desired spacings between piles,and cylindrical piles in this dimension could protect the pipeline against scour more effectively than cubical piles. 展开更多
关键词 Clear water River crossing pipeline Local scour Self-burial process Sediment transport
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Implementation of a Nesting Repair Technology for Transportation Pipeline Repair
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作者 Yijun Gao Yong Wang +2 位作者 Qing Na Jiawei Zhang Aixiang Wu 《Fluid Dynamics & Materials Processing》 EI 2024年第11期2443-2458,共16页
Filling methods in the mining industry can maximize the recovery of mineral resources and protect the underground and surface environments.In recent years,such methods have been widely used in metal mines where pipeli... Filling methods in the mining industry can maximize the recovery of mineral resources and protect the underground and surface environments.In recent years,such methods have been widely used in metal mines where pipeline transportation typically plays a decisive role in the safety and stability of the entirefilling system.Because thefilling slurry contains a large percentage of solid coarse particles,the involved pipeline is typically eroded and often damaged during such a process.A possible solution is the so-called nesting repair technology.In the present study,nesting a 127 mm outer diameter pipeline in 151 mm inner diameter borehole is considered to meet the repair objective.First,by using the rheological theory,the pipeline transmission resistance and self-flow conveying range are calculated under different working conditions.It is shown that the pipeline transmission resistance is larger when the inner diameter of casing is 80 mm,and the limitflow rate of vertical pipeline self-flow is 120 m^(3)/h;moreover,when the pipeline diameter is 100 mm and theflow rate is 140 m^(3)/h,the self-flow conveying can be satisfied in most of the underground−455 m stage.Accordingly,a plan is presented for the nesting repair strategy,based on the installation of a drill bit under the casing and lowering the casing into the borehole as if it were a drill pipe.Finally,the outcomes of such a strategy are verified.Thefillingflow rate range using the new pipelines is found to be in the range from 188.60 to 224.39 m^(3)/h,and its averagefillingflow rate reaches 209.83 m^(3)/h when conveying 2319.6 m long-distance quarry. 展开更多
关键词 BOREHOLE nesting repair pipeline transmission resistance flow rate
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Analysis of sensitivity to hydrate blockage risk in natural gas gathering pipeline
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作者 Ao-Yang Zhang Meng Cai +4 位作者 Na Wei Hai-Tao Li Chao Zhang Jun Pei Xin-Wei Wang 《Petroleum Science》 SCIE EI CAS CSCD 2024年第4期2723-2733,共11页
During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and... During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines,resulting in production reduction,shutdowns,and pressure build-ups.Consequently,a cascade of risks is prone to occur.To address this issue,this study focuses on the operational process of natural gas gathering and transmission pipelines,where a comprehensive framework is established.This framework includes theoretical models for pipeline temperature distribution,pipeline pressure distribution,multiphase flow within the pipeline,hydrate blockage,and numerical solution methods.By analyzing the influence of inlet temperature,inlet pressure,and terminal pressure on hydrate formation within the pipeline,the sensitivity patterns of hydrate blockage risks are derived.The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate,potentially mitigating pipeline blockage during natural gas transportation.Furthermore,an increase in inlet temperature and terminal pressure,and a decrease in inlet pressure,results in a displacement of the most probable location for hydrate blockage towards the terminal station.However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system,contradicting the operational goal of energy efficiency and reduction of energy consumption.Consequently,for high-pressure gathering pipelines,measures such as raising the inlet temperature or employing inhibitors,electrical heat tracing,and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation.Moreover,considering abnormal conditions such as gas well production and pipeline network shutdowns,which could potentially trigger hydrate formation,the installation of methanol injection connectors remains necessary to ensure production safety. 展开更多
关键词 Natural gas hydrates Gathering pipeline Temperature variation Hydrate formation rate Sensitivity analysis
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Stress corrosion cracking behavior of buried oil and gas pipeline steel under the coexistence of magnetic field and sulfate-reducing bacteria
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作者 Jian-Yu He Fei Xie +3 位作者 Dan Wang Guang-Xin Liu Ming Wu Yue Qin 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1320-1332,共13页
Magnetic field and microorganisms are important factors influencing the stress corrosion cracking(SCC)of buried oil and gas pipelines. Once SCC occurs in buried pipelines, it will cause serious hazards to the soil env... Magnetic field and microorganisms are important factors influencing the stress corrosion cracking(SCC)of buried oil and gas pipelines. Once SCC occurs in buried pipelines, it will cause serious hazards to the soil environment. The SCC behavior of X80 pipeline steel under the magnetic field and sulfate-reducing bacteria(SRB) environment was investigated by immersion tests, electrochemical tests, and slow strain rate tensile(SSRT) tests. The results showed that the corrosion and SCC sensitivity of X80 steel decreased with increasing the magnetic field strength in the sterile environment. The SCC sensitivity was higher in the biotic environment inoculated with SRB, but it also decreased with increasing magnetic field strength, which was due to the magnetic field reduces microbial activity and promotes the formation of dense film layer. This work provided theoretical guidance on the prevention of SCC in pipeline steel under magnetic field and SRB coexistence. 展开更多
关键词 Magnetic field Sulfate-reducing bacteria Film layer Stress corrosion cracking Oil and gas pipelines
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SDH-FCOS:An Efficient Neural Network for Defect Detection in Urban Underground Pipelines
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作者 Bin Zhou Bo Li +2 位作者 Wenfei Lan Congwen Tian Wei Yao 《Computers, Materials & Continua》 SCIE EI 2024年第1期633-652,共20页
Urban underground pipelines are an important infrastructure in cities,and timely investigation of problems in underground pipelines can help ensure the normal operation of cities.Owing to the growing demand for defect... Urban underground pipelines are an important infrastructure in cities,and timely investigation of problems in underground pipelines can help ensure the normal operation of cities.Owing to the growing demand for defect detection in urban underground pipelines,this study developed an improved defect detection method for urban underground pipelines based on fully convolutional one-stage object detector(FCOS),called spatial pyramid pooling-fast(SPPF)feature fusion and dual detection heads based on FCOS(SDH-FCOS)model.This study improved the feature fusion component of the model network based on FCOS,introduced an SPPF network structure behind the last output feature layer of the backbone network,fused the local and global features,added a top-down path to accelerate the circulation of shallowinformation,and enriched the semantic information acquired by shallow features.The ability of the model to detect objects with multiple morphologies was strengthened by introducing dual detection heads.The experimental results using an open dataset of underground pipes show that the proposed SDH-FCOS model can recognize underground pipe defects more accurately;the average accuracy was improved by 2.7% compared with the original FCOS model,reducing the leakage rate to a large extent and achieving real-time detection.Also,our model achieved a good trade-off between accuracy and speed compared with other mainstream methods.This proved the effectiveness of the proposed model. 展开更多
关键词 Urban underground pipelines defect detection SDH-FCOS feature fusion SPPF dual detection heads
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An Update on the Clinical Pipelines of New Antibacterial Drugs Developed in China
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作者 Xinyi Yang Congran Li +8 位作者 Xiukun Wang Zhonghui Zheng Peiyi Sun Chunjie Xu Luni Chen Jiandong Jiang Staffan Normark Birgitta Henriques-Normark Xuefu You 《Engineering》 SCIE EI CAS CSCD 2024年第7期52-68,共17页
Antibacterial resistance is a global health threat that requires further concrete action on the part of all countries.In this context,one of the biggest concerns is whether enough new antibacterial drugs are being dis... Antibacterial resistance is a global health threat that requires further concrete action on the part of all countries.In this context,one of the biggest concerns is whether enough new antibacterial drugs are being discovered and developed.Although several high-quality reviews on clinical antibacterial drug pipelines from a global perspective were published recently,none provides comprehensive information on original antibacterial drugs at clinical stages in China.In this review,we summarize the latest progress of novel antibacterial drugs approved for marketing and under clinical evaluation in China since 2019.Information was obtained by consulting official websites,searching commercial databases,retrieving literature,asking personnel from institutions or companies,and other means,and a considerable part of the data covered here has not been included in other reviews.As of June 30,2023,a total of 20 antibacterial projects from 17 Chinese pharmaceutical companies or developers were identified and updated.Among them,two new antibacterial drugs that belong to traditional antibiotic classes were approved by the National Medical Products Administration(NMPA)in China in 2019 and 2021,respectively,and 18 antibacterial agents are in clinical development,with one under regulatory evaluation,five in phase-3,six in phase-2,and six in phase-1.Most of the clinical candidates are new analogs or monocomponents of traditional antibacterial pharmacophore types,including two dual-acting hybrid antibiotics and a recombinant antibacterial protein.Overall,despite there being 17 antibacterial clinical candidates,our analysis indicates that there are still relatively few clinically differentiated antibacterial agents in stages of clinical development in China.Hopefully,Chinese pharmaceutical companies and institutions will develop more innovative and clinically differentiated candidates with good market potential in the future research and development(R&D)of original antibacterial drugs. 展开更多
关键词 Antimicrobial resistance New antibiotics Clinical pipelines WHO priority pathogens National Mega-Project for Innovative Drugs
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CFD Investigation of Diffusion Law and Harmful Boundary of Buried Natural Gas Pipeline in the Mountainous Environment
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作者 Liqiong Chen Kui Zhao +4 位作者 Kai Zhang Duo Xv Hongxvan Hu Guoguang Ma Wenwen Zhan 《Energy Engineering》 EI 2024年第8期2143-2165,共23页
The leakage gas from a buried natural gas pipelines has the great potential to cause economic losses and environmental pollution owing to the complexity of the mountainous environment.In this study,computational fluid... The leakage gas from a buried natural gas pipelines has the great potential to cause economic losses and environmental pollution owing to the complexity of the mountainous environment.In this study,computational fluid dynamics(CFD)method was applied to investigate the diffusion law and hazard range of buried natural gas pipeline leakage in mountainous environment.Based on cloud chart,concentration at the monitoring site and hazard range of lower explosion limit(LEL)and upper explosion limit(UEL),the influences of leakage hole direction and shape,soil property,burial depth,obstacle type on the diffusion law and hazard range are analyzed.Results show that the leakage gas is not radially diffused until it reaches the ground,and the velocity of gas diffusion to the ground and the hazard range decrease as the angle between the leaking direction and the buoyancy direction increases.Triangular and square leak holes have a faster diffusion rate and a wider hazard range than circular.The diffusion rate of leakage gas in soil rises as soil granularity and porosity increase.The time of leakage gas diffusion to the ground increases significantly with the increase of burial depth,and the hazard range reduces as burial depth increases.Boulder-type obstacles will alter the diffusion path of the leakage gas and accelerate the expansion of the hazard distance,while trench-type obstacles will cause the natural gas to accumulate in the trench and form a high concentration region slowing the expansion of the surface gas concentration. 展开更多
关键词 Mountainous environment buried pipeline leakage and diffusion hazard range numerical simulation
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Novel Methodologies for Preventing Crack Propagation in Steel Gas Pipelines Considering the Temperature Effect
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作者 Nurlan Zhangabay Ulzhan Ibraimova +4 位作者 Marco Bonopera Ulanbator Suleimenov Konstantin Avramov Maryna Chernobryvko Aigerim Yessengali 《Structural Durability & Health Monitoring》 EI 2025年第1期1-23,共23页
Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crac... Using the software ANSYS-19.2/Explicit Dynamics,this study performedfinite-element modeling of the large-diameter steel pipeline cross-section for the Beineu-Bozoy-Shymkent gas pipeline with a non-through straight crack,strengthened by steel wire wrapping.The effects of the thread tensile force of the steel winding in the form of single rings at the crack edges and the wires with different winding diameters and pitches were also studied.The results showed that the strengthening was preferably executed at a minimum value of the thread tensile force,which was 6.4%more effective than that at its maximum value.The analysis of the influence of the winding dia-meters showed that the equivalent stresses increased by 32%from the beginning of the crack growth until the wire broke.The increment in winding diameter decelerated the disclosure of the edge crack and reduced its length by 8.2%.The analysis of the influence of the winding pitch showed that decreasing the distance between the winding turns also led to a 33.6%reduction in the length of the straight crack and a 7.9%reduction in the maximum stres-ses on the strengthened pipeline cross-section.The analysis of the temperature effect on the pipeline material,within a range from-40℃ to+50℃,resulted in a crack length change of up to 5.8%.As the temperature dropped,the crack length decreased.Within such a temperature range,the maximum stresses were observed along the cen-tral area of the crack,which were equal to 413 MPa at+50℃ and 440 MPa at-40℃.The results also showed that the presence of the steel winding in the pipeline significantly reduced the length of crack propagation up to 8.4 times,depending on the temperature effect and design parameters of prestressing.This work integrated the existing methods for crack localization along steel gas pipelines. 展开更多
关键词 Crack propagation finite-element internal pressure PRESTRESSING steel gas pipeline temperature effect
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Dynamic plugging regulating strategy of pipeline robot based on reinforcement learning
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作者 Xing-Yuan Miao Hong Zhao 《Petroleum Science》 SCIE EI CAS CSCD 2024年第1期597-608,共12页
Pipeline isolation plugging robot (PIPR) is an important tool in pipeline maintenance operation. During the plugging process, the violent vibration will occur by the flow field, which can cause serious damage to the p... Pipeline isolation plugging robot (PIPR) is an important tool in pipeline maintenance operation. During the plugging process, the violent vibration will occur by the flow field, which can cause serious damage to the pipeline and PIPR. In this paper, we propose a dynamic regulating strategy to reduce the plugging-induced vibration by regulating the spoiler angle and plugging velocity. Firstly, the dynamic plugging simulation and experiment are performed to study the flow field changes during dynamic plugging. And the pressure difference is proposed to evaluate the degree of flow field vibration. Secondly, the mathematical models of pressure difference with plugging states and spoiler angles are established based on the extreme learning machine (ELM) optimized by improved sparrow search algorithm (ISSA). Finally, a modified Q-learning algorithm based on simulated annealing is applied to determine the optimal strategy for the spoiler angle and plugging velocity in real time. The results show that the proposed method can reduce the plugging-induced vibration by 19.9% and 32.7% on average, compared with single-regulating methods. This study can effectively ensure the stability of the plugging process. 展开更多
关键词 pipeline isolation plugging robot Plugging-induced vibration Dynamic regulating strategy Extreme learning machine Improved sparrow search algorithm Modified Q-learning algorithm
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