Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resista...Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resistance and low-temperature resistance,respectively.In order to develop type 120 emergency valverubber diaphragms with long-life and high-performance,low-temperatureresistant CR and NR were processed.Design/methodology/approach–The physical properties of the low-temperature-resistant CR and NRwere tested by low-temperature stretching,dynamic mechanical analysis,differential scanning calorimetryand thermogravimetric analysis.Single-valve and single-vehicle tests of type 120 emergency valves werecarried out for emergency diaphragms consisting of NR and CR.Findings–The low-temperature-resistant CR and NR exhibited excellent physical properties.The elasticityand low-temperature resistance of NR were superior to those of CR,whereas the mechanical properties of thetwo rubbers were similar in the temperature range of 0℃–150℃.The NR and CR emergency diaphragms metthe requirements of the single-valve test.In the low-temperature single-vehicle test,only the low-temperaturesensitivity test of the NR emergency diaphragm met the requirements.Originality/value–The innovation of this study is that it provides valuable data and experience for futuredevelopment of type 120 valve rubber diaphragms.展开更多
Industrial process plants use emergency shutdown valves(ESDVs)as safety barriers to protect against hazardous events,bringing the plant to a safe state when potential danger is detected.These ESDVs are used extensivel...Industrial process plants use emergency shutdown valves(ESDVs)as safety barriers to protect against hazardous events,bringing the plant to a safe state when potential danger is detected.These ESDVs are used extensively in offshore oil and gas processing plants and have been mandated in the design of such systems from national and international standards and legislation.This paper has used actual ESDV operating data from four mid/late life oil and gas production platforms in the North Sea to research operational relationships that are of interest to those responsible for the technical management and operation of ESDVs.The first of the two relationships is between the closure time(CT)of the ESDV and the time it remains in the open position,prior to the close command.It has been hypothesised that the CT of the ESDV is affected by the length of time that it has been open prior to being closed(Time since the last stroke).In addition to the general analysis of the data series,two sub-categories were created to further investigate this possible relationship for CT and these are“above mean”and“below mean”.The correlations(Pearson's based)resulting from this analysis are in the“weak”and“very weak”categories.The second relationship investigated was the effect of very frequent closures to assess if this improves the CT.ESDV operational records for six subjects were analysed to find closures that occurred within a 24 h period of each other.However,no discriminating trend was apparent where CT was impacted positively or negatively by the frequent closure group.It was concluded that the variance of ESDV closure time cannot be influenced by the technical management of the ESDV in terms of scheduling the operation of the ESDV.展开更多
The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of f...The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of fidelity between the device and the patient.As regenerative medicine is still in its infancy,the ongoing search for new and effective prosthetic alternatives continues to be essential and highly rewarding.Thanks in part to the progress of imaging and the benefits of 3D printing,previously unimagined emergent technologies are at hand.The emerging technologies of the last few decades and the near future will continue to greatly improve both the quality and quantity of patients' lives.They focus on minimally invasive technologies(keyhole surgery) and approaches for deployment of valves,stent-grafts,leadless pacemakers and adaptation of medical devices for destination therapy(assist devices and artificial hearts).In addition,specific blood conduits for the aortic valves together with the aortic arch and the pulmonary valves are considered.These breakthroughs are currently at various stages of development and acceptability.Innovative biomaterials were essential in the development of cardiovascular devices.They were and they still are the essential support for conduction prosthesis,but their place in signal prosthesis is being revisited.Any new development in medical devices has been frequently driven by surgeons and industry.The emergent technologies are introduced by pioneers.The risks and benefits of devices must be continuously reassessed during the lifetime of the implants based upon sound scientific principles of investigation,clinical experience of the users and retrieval programs.展开更多
基金funded by the Science and Technology Research and Development Plan of the China State Railway Group Company Limited(No.N2023J053).
文摘Purpose–The type 120 emergency valve is an essential braking component of railway freight trains,butcorresponding diaphragms consisting of natural rubber(NR)and chloroprene rubber(CR)exhibit insufficientaging resistance and low-temperature resistance,respectively.In order to develop type 120 emergency valverubber diaphragms with long-life and high-performance,low-temperatureresistant CR and NR were processed.Design/methodology/approach–The physical properties of the low-temperature-resistant CR and NRwere tested by low-temperature stretching,dynamic mechanical analysis,differential scanning calorimetryand thermogravimetric analysis.Single-valve and single-vehicle tests of type 120 emergency valves werecarried out for emergency diaphragms consisting of NR and CR.Findings–The low-temperature-resistant CR and NR exhibited excellent physical properties.The elasticityand low-temperature resistance of NR were superior to those of CR,whereas the mechanical properties of thetwo rubbers were similar in the temperature range of 0℃–150℃.The NR and CR emergency diaphragms metthe requirements of the single-valve test.In the low-temperature single-vehicle test,only the low-temperaturesensitivity test of the NR emergency diaphragm met the requirements.Originality/value–The innovation of this study is that it provides valuable data and experience for futuredevelopment of type 120 valve rubber diaphragms.
文摘Industrial process plants use emergency shutdown valves(ESDVs)as safety barriers to protect against hazardous events,bringing the plant to a safe state when potential danger is detected.These ESDVs are used extensively in offshore oil and gas processing plants and have been mandated in the design of such systems from national and international standards and legislation.This paper has used actual ESDV operating data from four mid/late life oil and gas production platforms in the North Sea to research operational relationships that are of interest to those responsible for the technical management and operation of ESDVs.The first of the two relationships is between the closure time(CT)of the ESDV and the time it remains in the open position,prior to the close command.It has been hypothesised that the CT of the ESDV is affected by the length of time that it has been open prior to being closed(Time since the last stroke).In addition to the general analysis of the data series,two sub-categories were created to further investigate this possible relationship for CT and these are“above mean”and“below mean”.The correlations(Pearson's based)resulting from this analysis are in the“weak”and“very weak”categories.The second relationship investigated was the effect of very frequent closures to assess if this improves the CT.ESDV operational records for six subjects were analysed to find closures that occurred within a 24 h period of each other.However,no discriminating trend was apparent where CT was impacted positively or negatively by the frequent closure group.It was concluded that the variance of ESDV closure time cannot be influenced by the technical management of the ESDV in terms of scheduling the operation of the ESDV.
基金"111 Project" Biomedical Textile Material Science and Technology,China(No.B07024)National Natural Science Foundations of China(Nos.31100682,81371648)+2 种基金the Shanghai Construction of College Experiment Technique Team Project,China(No.101-07.0053014)the Fundamental Research Funds for the Central University,China(No.15D110126)the Department of Surgery at Laval University,Quebec and the Fonds de Recherche en Chirurgie Vasculaire of the CHU,Quebec,Canada
文摘The optimal vascular blood supply throughout the body guarantees the support of normal functions to tissues and organs.Implants are now becoming a seamless extension of the body and shall accompany a higher level of fidelity between the device and the patient.As regenerative medicine is still in its infancy,the ongoing search for new and effective prosthetic alternatives continues to be essential and highly rewarding.Thanks in part to the progress of imaging and the benefits of 3D printing,previously unimagined emergent technologies are at hand.The emerging technologies of the last few decades and the near future will continue to greatly improve both the quality and quantity of patients' lives.They focus on minimally invasive technologies(keyhole surgery) and approaches for deployment of valves,stent-grafts,leadless pacemakers and adaptation of medical devices for destination therapy(assist devices and artificial hearts).In addition,specific blood conduits for the aortic valves together with the aortic arch and the pulmonary valves are considered.These breakthroughs are currently at various stages of development and acceptability.Innovative biomaterials were essential in the development of cardiovascular devices.They were and they still are the essential support for conduction prosthesis,but their place in signal prosthesis is being revisited.Any new development in medical devices has been frequently driven by surgeons and industry.The emergent technologies are introduced by pioneers.The risks and benefits of devices must be continuously reassessed during the lifetime of the implants based upon sound scientific principles of investigation,clinical experience of the users and retrieval programs.
