A remote-control tether-less isolation tool is a mechanical device that is normally used in pipelines to block the flow at a given position by transforming a blocking module. In this study, the interactions between th...A remote-control tether-less isolation tool is a mechanical device that is normally used in pipelines to block the flow at a given position by transforming a blocking module. In this study, the interactions between the fluid and the plug module of the isolation tool were investigated. Simulations of the plug process and particle image velocimetry measurements were performed to study the flow characteristics. Numerical solutions for the continuity, momentum, and energy equations were obtained by using commercial software based on finite-volume techniques. Box–Behnken design was applied, and response surface methodology（RSM）-based CFD simulation analysis was conducted. The dynamic model in the plug process was built by RSM and used to evaluate the influences of the main mechanical parameters on the pressure during the plug process. The diameter of the isolation tool and the diameter of the plug module have strong influences on the process, and the length of the isolation tool has only a little influence on the plug process.展开更多
目的:对肺癌幸存者社会疏离的研究现状、影响因素、评估工具进行范围综述,为临床医护人员制定干预措施提供研究思路。方法:采用范围综述的框架,系统检索中国知网、万方、维普网、中国生物医学文献数据库、Embase、PubMed、Web of Scienc...目的:对肺癌幸存者社会疏离的研究现状、影响因素、评估工具进行范围综述,为临床医护人员制定干预措施提供研究思路。方法:采用范围综述的框架,系统检索中国知网、万方、维普网、中国生物医学文献数据库、Embase、PubMed、Web of Science、CINAHL及Cochrane Library中收录的肺癌幸存者社会疏离的相关研究,检索时限为建库至2023年3月18日。结果:共纳入18篇文献,研究区域分布于亚洲、北美洲、欧洲三大洲,包括中国、美国、西班牙等7个国家,研究工具中使用较为频繁的为加利福尼亚大学洛杉矶分校孤独量表和癌症孤独感量表。患者社会疏离的发生率和严重程度在不同研究结果之间存在一定差异。肺癌幸存者社会疏离的影响因素包括人口学因素、疾病相关因素、症状因素及心理社会因素。结论:肺癌幸存者社会疏离在一定程度上会影响患者的生存质量,虽然目前肺癌幸存者社会疏离的测评工具种类较多,但总体上缺乏特异性评估工具,提示医护人员在今后构建相关测评工具时可考虑增加特异性研究工具的开发和应用,根据影响因素制定个性化的干预措施,以帮助患者减轻社会疏离。展开更多
During the pipeline plugging process,both the pipeline and the pipe isolation tool(PIT)will be greatly damaged,due to the violent vibration of the flow field.In this study,it was proposed for the first time to reduce ...During the pipeline plugging process,both the pipeline and the pipe isolation tool(PIT)will be greatly damaged,due to the violent vibration of the flow field.In this study,it was proposed for the first time to reduce the vibration of the flow field during the plugging process by optimizing the surface structure of the PIT.Firstly,the central composite design(CCD)was used to obtain the optimization schemes,and the drag coefficient and pressure coefficient were proposed to evaluate the degree of flow field changes.Secondly,a series of computational fluid dynamics(CFD)simulations were performed to obtain the drag coefficient and pressure coefficient during dynamic plugging.And the mathematical model of drag coefficient and pressure coefficient with the surface structure of the PIT were established respectively.Then,a modified particle swarm optimization(PSO)was applied to predict the optimal value of the surface structure of the PIT.Finally,an experimental rig was built to verify the effectiveness of the optimization.The results showed that the improved method could reduce the flow field vibration by 49.56%.This study provides a reference for the design of the PIT surface structure for flow field vibration technology.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 51575528)the Scientific Research Foundation of the Education Ministry for Returned Chinese Scholars (China)+1 种基金the State Key Laboratory for Coal Resources and Safe Mining, China University of Mining and Technology (No. SKLCRSM10KFB04)the Science Foundation of China University of Petroleum, Beijing (No. YXQN-2014-02)
文摘A remote-control tether-less isolation tool is a mechanical device that is normally used in pipelines to block the flow at a given position by transforming a blocking module. In this study, the interactions between the fluid and the plug module of the isolation tool were investigated. Simulations of the plug process and particle image velocimetry measurements were performed to study the flow characteristics. Numerical solutions for the continuity, momentum, and energy equations were obtained by using commercial software based on finite-volume techniques. Box–Behnken design was applied, and response surface methodology（RSM）-based CFD simulation analysis was conducted. The dynamic model in the plug process was built by RSM and used to evaluate the influences of the main mechanical parameters on the pressure during the plug process. The diameter of the isolation tool and the diameter of the plug module have strong influences on the process, and the length of the isolation tool has only a little influence on the plug process.
文摘目的:对肺癌幸存者社会疏离的研究现状、影响因素、评估工具进行范围综述,为临床医护人员制定干预措施提供研究思路。方法:采用范围综述的框架,系统检索中国知网、万方、维普网、中国生物医学文献数据库、Embase、PubMed、Web of Science、CINAHL及Cochrane Library中收录的肺癌幸存者社会疏离的相关研究,检索时限为建库至2023年3月18日。结果:共纳入18篇文献,研究区域分布于亚洲、北美洲、欧洲三大洲,包括中国、美国、西班牙等7个国家,研究工具中使用较为频繁的为加利福尼亚大学洛杉矶分校孤独量表和癌症孤独感量表。患者社会疏离的发生率和严重程度在不同研究结果之间存在一定差异。肺癌幸存者社会疏离的影响因素包括人口学因素、疾病相关因素、症状因素及心理社会因素。结论:肺癌幸存者社会疏离在一定程度上会影响患者的生存质量,虽然目前肺癌幸存者社会疏离的测评工具种类较多,但总体上缺乏特异性评估工具,提示医护人员在今后构建相关测评工具时可考虑增加特异性研究工具的开发和应用,根据影响因素制定个性化的干预措施,以帮助患者减轻社会疏离。
基金financially supported by the National Natural Science Foundation of China(Grant No.51575528)。
文摘During the pipeline plugging process,both the pipeline and the pipe isolation tool(PIT)will be greatly damaged,due to the violent vibration of the flow field.In this study,it was proposed for the first time to reduce the vibration of the flow field during the plugging process by optimizing the surface structure of the PIT.Firstly,the central composite design(CCD)was used to obtain the optimization schemes,and the drag coefficient and pressure coefficient were proposed to evaluate the degree of flow field changes.Secondly,a series of computational fluid dynamics(CFD)simulations were performed to obtain the drag coefficient and pressure coefficient during dynamic plugging.And the mathematical model of drag coefficient and pressure coefficient with the surface structure of the PIT were established respectively.Then,a modified particle swarm optimization(PSO)was applied to predict the optimal value of the surface structure of the PIT.Finally,an experimental rig was built to verify the effectiveness of the optimization.The results showed that the improved method could reduce the flow field vibration by 49.56%.This study provides a reference for the design of the PIT surface structure for flow field vibration technology.
