Carbon capture and storage(CCS)has been proposed as a potential technology to mitigate climate change.However,there is currently a huge gap between the current global deployment of this technology and that which will ...Carbon capture and storage(CCS)has been proposed as a potential technology to mitigate climate change.However,there is currently a huge gap between the current global deployment of this technology and that which will be ultimately required.Whilst CO2 can be captured at any geographic location,storage of CO2 will be constrained by the geological storage potential in the area the CO2 is captured.The geological storage potential can be evaluated at a very high level according to the tectonic setting of the target area.To date,CCS deployment has been restricted to more favourable tectonic settings,such as extensional passive margin and post-rift basins and compressional foreland basins.However,to reach the adequate level of deployment,the potential for CCS of regions in different tectonic settings needs to be explored and assessed worldwide.Surprisingly,the potential of compressional basins for carbon storage has not been universally evaluated according to the global and regional carbon emission distribution.Here,we present an integrated source-to-sink analysis tool that combines comprehensive,open-access information on basin distribution,hydrocarbon resources and CO2 emissions based on geographical information systems(GIS).Compressional settings host some of the most significant hydrocarbon-bearing basins and 36% of inland CO2 emissions but,to date,large-scale CCS facilities in compressional basins are concentrated in North America and the Middle East only.Our source-to-sink tool allows identifying five high-priority regions for prospective CCS development in compressional basins:North America,north-western South America,south-eastern Europe,the western Middle East and western China.We present a study of the characteristics of these areas in terms of CO2 emissions and CO2 storage potential.Additionally,we conduct a detailed case-study analysis of the Sichuan Basin(China),one of the compressional basins with the greatest CO2 storage potential.Our results indicate that compressional basins will have to play a critical role in the future of CCS if this technology is to be implemented worldwide.展开更多
The aim of this study was to develop an efficient and realistic response surface optimization technique for the design of V-belt drive for optimum power output of the drive in machinery design. Optimization mathematic...The aim of this study was to develop an efficient and realistic response surface optimization technique for the design of V-belt drive for optimum power output of the drive in machinery design. Optimization mathematical model of the V-belt drive was constructed. The power output of the belt drive was modeled and optimized by the Response Surface Methodology (RSM). Analysis of variance was used to evaluate the extent of influence of each independent variables on the power output response of the belt drive. A RSM optimization process was proposed to calculate optimal power output for V-belt drive given a set of pulley diameter for the drive employed in a tilling machine. The analysis showed that optimum power output of the drive for workshop light operation machinery could be obtained at driving and driven pulley radius range of 550 - 900 mm and 250 - 500 mm. An optimum power output of 1418.76 kW was obtained at driving and driven pulley radius of 846 and 486 mm respectively for a farm tilling machine.展开更多
The non-stationary buffeting response of long span suspension bridge in time domain under strong wind loading is computed. Modeling method for generating non-stationary fluctuating winds with probabilistic model for n...The non-stationary buffeting response of long span suspension bridge in time domain under strong wind loading is computed. Modeling method for generating non-stationary fluctuating winds with probabilistic model for non-stationary strong wind fields is first presented. Non-stationary wind forces induced by strong winds on bridge deck and tower are then given a brief introduction. Finally,Non-stationary buffeting response of Pulite Bridge in China,a long span suspension bridge,is computed by using ANSYS software under four working conditions with different combination of time-varying mean wind and time-varying variance. The case study further confirms that it is necessity of considering non-stationary buffeting response for long span suspension bridge under strong wind loading,rather than only stationary buffeting response.展开更多
In this study, a number of nonlinear time-history dynamic analyses are conducted on a part of Tehran water distribution network to investigate its functionality during transient large ground motions. The network is of...In this study, a number of nonlinear time-history dynamic analyses are conducted on a part of Tehran water distribution network to investigate its functionality during transient large ground motions. The network is of 950-meter length, consisting of ductile iron pipes segments of 6-meter length. Pipes are modeled using beam elements and springs characterize the connections. Considering the time lag between support inputs, and the nonlinear soil-pipe interaction, by scaling the amplitude of the Tab as earthquake record, incremental dynamic analysis is carried out on the network in two orthogonal directions and the sensitivity of the network response is examined. Furthermore, the effects of variations in soil damping and soil spring stiffness are also studied in the network analysis. Finally the effect of changes in angle between incoming wave and pipeline is considered on a simplified network. Results show that the points other than critical ones at network intersections remain almost intact and when the angle of incidence is 30 degrees the stress and rotation peak.展开更多
In this study, a new method is proposed to evaluate the seismic behavior of buried jointed water pipeline networks subjected to wave propagation. First, using finite element method and solid elements, different kinds ...In this study, a new method is proposed to evaluate the seismic behavior of buried jointed water pipeline networks subjected to wave propagation. First, using finite element method and solid elements, different kinds of currently used connections in the network are modeled, and their nonlinear behavior in all directions is obtained. Second, a 950-meter long network consisting of ductile iron pipes segments of 6-meter length and springs characterizing the connections, are modeled using beam elements. Three-component displacement record of the Tabas earthquake is applied to the network considering the time lag between support inputs, and the nonlinear soil-pipe interaction. The record is applied once in North-South direction and once in East-West direction with different wave propagation velocities. Results of interest such as stress values and rotations at various points of the network are then obtained, and critical points are introduced in each direction. Results show that the points other than the critical ones at the network intersections remain elastic.展开更多
Background:Knowing the variability of blood coagulation responses to liver damage of different origins can provide a key to curing liver tissues or to mitigating treatment side effects.The aim of the present work was ...Background:Knowing the variability of blood coagulation responses to liver damage of different origins can provide a key to curing liver tissues or to mitigating treatment side effects.The aim of the present work was to compare the changes in the main components of hemostasis under experimental drug-induced hepatosis and hepatitis in rats.Methods:We modeled diclofenac-induced hepatitis and tetracycline-induced hepa-tosis.Hemostasis response was gauged by measuring fibrinogen,factor X,protein C(PC),and prothrombin in plasma.The decarboxylated form of prothrombin was de-tected by measuring prothrombin index and ecamulin index.Platelet reactivity was studied using aggregometry.Results:Both hepatitis and hepatosis decreased the synthesis of fibrinogen,factor X,and prothrombin.However,protein carboxylation was not disrupted in hepatosis but was much impaired in hepatitis.PC decreased in both models as a consequence of its consumption possibly during inflammatory response.Platelet aggregation rate was lower in hepatosis but higher in hepatitis.Conclusions:Our findings imply the need for a thorough monitoring of the hemostasis system in liver diseases to avoid possible thrombotic complications.Its state indicates the disorder's rate and character.展开更多
Objectives:The aim of this multicenter,prospective,single-arm pilot study(ClinicalTrials.gov number:NCT05040074)was to observe the procedural and 30-day results of the novel transcatheter mitral valve repair system,SQ...Objectives:The aim of this multicenter,prospective,single-arm pilot study(ClinicalTrials.gov number:NCT05040074)was to observe the procedural and 30-day results of the novel transcatheter mitral valve repair system,SQ-Kyrin■-M Clip(Shenqi Medical,Shanghai,China),in patients with severe mitral regurgitation(MR).Methods:The heart team considered patients from 5 centers in China with clinically significant functional mitral regurgitation≥3+despite optimal medical therapy or degenerative mitral regurgitation≥3+with high surgical risk as candidates for transcatheter repair.All patients received transcatheter edge-to-edge mitral valve repair under general anesthesia.The primary outcome was technical success,which included all of the following measured at the exit from the catheterization laboratory:(1)absence of procedural mortality;(2)successful access,delivery,and retrieval of the device delivery system;(3)successful deployment and correct positioning of the frst intended device;and(4)no emergency surgery or reintervention related to the device or access procedure.The secondary outcomes included all-cause mortality,serious adverse events,device success,and procedural success 30 d after the intervention.Results:From June 2021 to December 2021,18 patients were enrolled in this study with age(75.7±7.4)years.Fifteen patients had MR 4+,while 3 had MR 3+.Technical success was achieved in all patients,including 6 degenerative mitral regurgitation and 12 functional mitral regurgitation patients.There was no all-cause mortality at 30 d.One patient had single leaflet device attachment within 30 d,which was regarded as a serious adverse event,and the patient was successfully treated with reintervention by implanting another clip.Another patient's transmitral gradient was 6 mmHg(>5 mmHg),with an effective orifice area of 2.57 cm^(2) after the procedure.Sixteen patients had device success and procedural success at 30 d postoperation.Fourteen patients had MR 1+,3 had MR 2+,and only 1 patient had MR 3+30 d after the procedure.Conclusions:The results of this feasibility study showed the efficacy and safety of the SQ-Kyrin■-M device in the Chinese population with severe MR,laying a solid foundation for a subsequent large-scale confirmatory study.展开更多
An effective and simple way to develop equations from impact strain signals was proposed.Little research has been performed in this area,but this equation is very important for evaluating input signals in finite eleme...An effective and simple way to develop equations from impact strain signals was proposed.Little research has been performed in this area,but this equation is very important for evaluating input signals in finite element analysis impact tests and for obtaining additional information on material deformation and fracture processes under impact loading.For this purpose,dynamic impact responses were examined through signals obtained from a strain gauge installed on an impact striker connected to a data acquisition system.Aluminium 6061-T6 was used to extract strain responses on the striker during Charpy impact testing.Statistical analysis was performed using the I-kaz method,and curve fitting equations based on the equation for vibration response under a non-periodic force were used to evaluate the Charpy impact signals.The I-kaz coefficients and curve fitting equations were then compared and discussed with related parameters,such as velocities and thicknesses.Velocity and thickness were found to be related to the strain signal patterns,curve fitting equations and I-kaz coefficients.The equations developed using this method had R2 values greater than 97.7%.Finally,the constructed equations were determined to be suitable for evaluating Charpy impact strain signal patterns and obtaining additional information on fracture processes under impact loading.展开更多
An equiatomic CoCrFeNiMn High Entropy Alloy(HEA)was in-situ deposited by the powder-bed arc ad-ditive manufacturing(PBAAM)process for the first time.Comparative research was conducted on the evolution of phase,crystal...An equiatomic CoCrFeNiMn High Entropy Alloy(HEA)was in-situ deposited by the powder-bed arc ad-ditive manufacturing(PBAAM)process for the first time.Comparative research was conducted on the evolution of phase,crystallographic orientation,dislocation morphology,precipitation,and mechanical performance with the accumulation of inter-layer remelting times.The experimental outcomes mani-fested that the PBAAMed CoCrFeNiMn HEA consists of a stable solid-solution FCC structure,with de-creased lattice parameter but slightly increased(full width at half maximum)FWHM as the accumulation of the inter-layer remelting.The{001}<100>cube texture with a weakened texture intensity was de-tected with an increment of inter-layer remelting frequency from once to 5 times,yet it was transformed into{011}<100>Goss texture with a further increase to 7 times.Additionally,the mean grain diameter distinctly decreased,while the volume fraction of(low angle grain boundaries)LAGBs and dislocation density remarkably added up as the accumulated inter-layer remelts.Predominant cellular substructure generated in all process conditions and could be easily differentiated by elemental segregation.Both theσand M 23 C 6 Cr-rich precipitates in nano-scale and submicron MnS precipitate were detected on the grain boundaries of the PBAAMed deposited components,with a rather sparse distribution.Speaking of mechanical performance,the YS,UTS,and hardening rate are generally increased while the UE is grad-ually decreased as increased inter-layer remelting times.The studied PBAAMed CoCrFeNiMn HEA pos-sesses comparable mechanical performances with the counterparts of laser-deposited and as-cast ones.The strengthening mechanisms of the studied material are predominantly the grain boundary strength-ening and dislocation strengthening.This investigation would be a valuable resource in the research field of fabricating HEA alloys with acceptable microstructure and properties using the PBAAM method.展开更多
The EFVM (Vitoria Minas Railroad) is one of the main railways in Brazil. It transports freight trains of ore, 220 wagons each. These wagons have 2 boogies of 2 axles each and 32 metric tons on metre gauge. Elastic s...The EFVM (Vitoria Minas Railroad) is one of the main railways in Brazil. It transports freight trains of ore, 220 wagons each. These wagons have 2 boogies of 2 axles each and 32 metric tons on metre gauge. Elastic strains were measured on a special part of this railway due to these trains. The main load to evaluate stresses and strains was a G 16 Locomotive, a C-C kind from Vale, a Brazilian Company. The measurements were obtained by dynamic deflectometer installed on a main line of this railway, near Ipatinga, a city from Minas Gerais, one of Brazil states. This track was equipped to obtain stresses under an equal repeated static load A simulation of the stresses was made under critical strain by Ferrovia 1.0 software. It was also made an evaluation of unequal results from neighbor sleepers taking in comparison two equipped parts of this railway, one with compacted ballast and no compaction to the other. The results were strain limited, avoiding breakage or damage to the studied rails. This work analyses these measurements focusing on the improvement of track quality.展开更多
Background:Due to the wide variety of morphology,size,and dynamics,selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation(PPVI).This study aimed to report our ...Background:Due to the wide variety of morphology,size,and dynamics,selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation(PPVI).This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional(3D)-printed models for planning PPVI with the Venus P-valve.Methods:Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University.Results:3D model bench testing altered treatment strategy in all patients(100%).One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly.In the remaining 14 patients,valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery.In four patients,it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract(RVOT)(n=2)or risk of compression coronary artery(n=2).Concerning sizing,we found that an oversize of 2-5 mm suffices.Anchoring of the valve was dictated by the flaring of the in-and outflow portion in the pulmonary artery.PPVI was successful in all 14 patients(absence of valve migration,no coronary compression,and none-to-mild residual pulmonary regurgitation[PR]).The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group(36[2]vs.32[4],Z=-3.77,P<0.001).Conclusions:In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique,as 2-5 mm sufficed.展开更多
Transcatheter edge-to-edge repair(TEER)of the mitral valve has emerged as a standard treatment for patients with severe degenerative mitral regurgitation at high or prohibitive surgical risk.The devices approved by th...Transcatheter edge-to-edge repair(TEER)of the mitral valve has emerged as a standard treatment for patients with severe degenerative mitral regurgitation at high or prohibitive surgical risk.The devices approved by the Food and Drug Administration including MitraClip(Abbott Vascular,California,USA)and PASCAL(Edwards Lifesciences,California,USA)cost over$33,000 in western countries.[1]This pricing presents a significant economic burden especially in developing countries,where TEER devices are typically not covered by health insurance.展开更多
Mitral valve regurgitation(MR)is a common heart valve disease that affects>10%of the elderly population.Epidemiological data estimate that the number of MR patients has reached more than2.5 million in the USA,with ...Mitral valve regurgitation(MR)is a common heart valve disease that affects>10%of the elderly population.Epidemiological data estimate that the number of MR patients has reached more than2.5 million in the USA,with an extremely low surgical intervention rate(<5%)[1].展开更多
基金the framework of DGICYT Spanish Projects CGL2015-66335-C2-1-R and PGC2018-093903-B-C22Grup Consolidat de Recerca“Geologia Sedimentaria”(2017-SGR-824)+5 种基金funded by the China Scholarship Council(CSC)(201806450043)JA received funding by EIT Raw Materials–SIT4ME Project(17024)funded by MICINN(Juan de la Cierva fellowship-IJC2018-036074-I)funding by the AGAUR(Agencia de Gestio d’Ajuts Universitaris i de Recerca)of the Generalitat de Catalunya(“Beatriu de Pinos”fellowship 2017SGR-824)the Spanish Ministry of Science,Innovation and Universities(“Ramon y Cajal”fellowship RYC2018-026335-I)funded by the University of Strathclyde Faculty of Engineering。
文摘Carbon capture and storage(CCS)has been proposed as a potential technology to mitigate climate change.However,there is currently a huge gap between the current global deployment of this technology and that which will be ultimately required.Whilst CO2 can be captured at any geographic location,storage of CO2 will be constrained by the geological storage potential in the area the CO2 is captured.The geological storage potential can be evaluated at a very high level according to the tectonic setting of the target area.To date,CCS deployment has been restricted to more favourable tectonic settings,such as extensional passive margin and post-rift basins and compressional foreland basins.However,to reach the adequate level of deployment,the potential for CCS of regions in different tectonic settings needs to be explored and assessed worldwide.Surprisingly,the potential of compressional basins for carbon storage has not been universally evaluated according to the global and regional carbon emission distribution.Here,we present an integrated source-to-sink analysis tool that combines comprehensive,open-access information on basin distribution,hydrocarbon resources and CO2 emissions based on geographical information systems(GIS).Compressional settings host some of the most significant hydrocarbon-bearing basins and 36% of inland CO2 emissions but,to date,large-scale CCS facilities in compressional basins are concentrated in North America and the Middle East only.Our source-to-sink tool allows identifying five high-priority regions for prospective CCS development in compressional basins:North America,north-western South America,south-eastern Europe,the western Middle East and western China.We present a study of the characteristics of these areas in terms of CO2 emissions and CO2 storage potential.Additionally,we conduct a detailed case-study analysis of the Sichuan Basin(China),one of the compressional basins with the greatest CO2 storage potential.Our results indicate that compressional basins will have to play a critical role in the future of CCS if this technology is to be implemented worldwide.
文摘The aim of this study was to develop an efficient and realistic response surface optimization technique for the design of V-belt drive for optimum power output of the drive in machinery design. Optimization mathematical model of the V-belt drive was constructed. The power output of the belt drive was modeled and optimized by the Response Surface Methodology (RSM). Analysis of variance was used to evaluate the extent of influence of each independent variables on the power output response of the belt drive. A RSM optimization process was proposed to calculate optimal power output for V-belt drive given a set of pulley diameter for the drive employed in a tilling machine. The analysis showed that optimum power output of the drive for workshop light operation machinery could be obtained at driving and driven pulley radius range of 550 - 900 mm and 250 - 500 mm. An optimum power output of 1418.76 kW was obtained at driving and driven pulley radius of 846 and 486 mm respectively for a farm tilling machine.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51408174)Anhui Provincial Natural Science Foundation(Grant No.1408085QE95)+1 种基金China Postdoctoral Science Foundation(Grant No.2013M540511 and 2015T80652)Key University Science Research Project of Anhui Province(Grant No.KJ2016A294)
文摘The non-stationary buffeting response of long span suspension bridge in time domain under strong wind loading is computed. Modeling method for generating non-stationary fluctuating winds with probabilistic model for non-stationary strong wind fields is first presented. Non-stationary wind forces induced by strong winds on bridge deck and tower are then given a brief introduction. Finally,Non-stationary buffeting response of Pulite Bridge in China,a long span suspension bridge,is computed by using ANSYS software under four working conditions with different combination of time-varying mean wind and time-varying variance. The case study further confirms that it is necessity of considering non-stationary buffeting response for long span suspension bridge under strong wind loading,rather than only stationary buffeting response.
文摘In this study, a number of nonlinear time-history dynamic analyses are conducted on a part of Tehran water distribution network to investigate its functionality during transient large ground motions. The network is of 950-meter length, consisting of ductile iron pipes segments of 6-meter length. Pipes are modeled using beam elements and springs characterize the connections. Considering the time lag between support inputs, and the nonlinear soil-pipe interaction, by scaling the amplitude of the Tab as earthquake record, incremental dynamic analysis is carried out on the network in two orthogonal directions and the sensitivity of the network response is examined. Furthermore, the effects of variations in soil damping and soil spring stiffness are also studied in the network analysis. Finally the effect of changes in angle between incoming wave and pipeline is considered on a simplified network. Results show that the points other than critical ones at network intersections remain almost intact and when the angle of incidence is 30 degrees the stress and rotation peak.
文摘In this study, a new method is proposed to evaluate the seismic behavior of buried jointed water pipeline networks subjected to wave propagation. First, using finite element method and solid elements, different kinds of currently used connections in the network are modeled, and their nonlinear behavior in all directions is obtained. Second, a 950-meter long network consisting of ductile iron pipes segments of 6-meter length and springs characterizing the connections, are modeled using beam elements. Three-component displacement record of the Tabas earthquake is applied to the network considering the time lag between support inputs, and the nonlinear soil-pipe interaction. The record is applied once in North-South direction and once in East-West direction with different wave propagation velocities. Results of interest such as stress values and rotations at various points of the network are then obtained, and critical points are introduced in each direction. Results show that the points other than the critical ones at the network intersections remain elastic.
基金National Academy of Sciences of Ukraine research,Grant/Award Number:0119U002512。
文摘Background:Knowing the variability of blood coagulation responses to liver damage of different origins can provide a key to curing liver tissues or to mitigating treatment side effects.The aim of the present work was to compare the changes in the main components of hemostasis under experimental drug-induced hepatosis and hepatitis in rats.Methods:We modeled diclofenac-induced hepatitis and tetracycline-induced hepa-tosis.Hemostasis response was gauged by measuring fibrinogen,factor X,protein C(PC),and prothrombin in plasma.The decarboxylated form of prothrombin was de-tected by measuring prothrombin index and ecamulin index.Platelet reactivity was studied using aggregometry.Results:Both hepatitis and hepatosis decreased the synthesis of fibrinogen,factor X,and prothrombin.However,protein carboxylation was not disrupted in hepatosis but was much impaired in hepatitis.PC decreased in both models as a consequence of its consumption possibly during inflammatory response.Platelet aggregation rate was lower in hepatosis but higher in hepatitis.Conclusions:Our findings imply the need for a thorough monitoring of the hemostasis system in liver diseases to avoid possible thrombotic complications.Its state indicates the disorder's rate and character.
基金supported by the National Key Project of Research and Development Plan during the fourteenth Five-year Plan Period(2022YFC2503400).
文摘Objectives:The aim of this multicenter,prospective,single-arm pilot study(ClinicalTrials.gov number:NCT05040074)was to observe the procedural and 30-day results of the novel transcatheter mitral valve repair system,SQ-Kyrin■-M Clip(Shenqi Medical,Shanghai,China),in patients with severe mitral regurgitation(MR).Methods:The heart team considered patients from 5 centers in China with clinically significant functional mitral regurgitation≥3+despite optimal medical therapy or degenerative mitral regurgitation≥3+with high surgical risk as candidates for transcatheter repair.All patients received transcatheter edge-to-edge mitral valve repair under general anesthesia.The primary outcome was technical success,which included all of the following measured at the exit from the catheterization laboratory:(1)absence of procedural mortality;(2)successful access,delivery,and retrieval of the device delivery system;(3)successful deployment and correct positioning of the frst intended device;and(4)no emergency surgery or reintervention related to the device or access procedure.The secondary outcomes included all-cause mortality,serious adverse events,device success,and procedural success 30 d after the intervention.Results:From June 2021 to December 2021,18 patients were enrolled in this study with age(75.7±7.4)years.Fifteen patients had MR 4+,while 3 had MR 3+.Technical success was achieved in all patients,including 6 degenerative mitral regurgitation and 12 functional mitral regurgitation patients.There was no all-cause mortality at 30 d.One patient had single leaflet device attachment within 30 d,which was regarded as a serious adverse event,and the patient was successfully treated with reintervention by implanting another clip.Another patient's transmitral gradient was 6 mmHg(>5 mmHg),with an effective orifice area of 2.57 cm^(2) after the procedure.Sixteen patients had device success and procedural success at 30 d postoperation.Fourteen patients had MR 1+,3 had MR 2+,and only 1 patient had MR 3+30 d after the procedure.Conclusions:The results of this feasibility study showed the efficacy and safety of the SQ-Kyrin■-M device in the Chinese population with severe MR,laying a solid foundation for a subsequent large-scale confirmatory study.
基金Universiti Kebangsaan Malaysia grant UKM-KK-03-FRGS 0118-2010Universiti Teknikal Malaysia Melaka for supporting these research activities
文摘An effective and simple way to develop equations from impact strain signals was proposed.Little research has been performed in this area,but this equation is very important for evaluating input signals in finite element analysis impact tests and for obtaining additional information on material deformation and fracture processes under impact loading.For this purpose,dynamic impact responses were examined through signals obtained from a strain gauge installed on an impact striker connected to a data acquisition system.Aluminium 6061-T6 was used to extract strain responses on the striker during Charpy impact testing.Statistical analysis was performed using the I-kaz method,and curve fitting equations based on the equation for vibration response under a non-periodic force were used to evaluate the Charpy impact signals.The I-kaz coefficients and curve fitting equations were then compared and discussed with related parameters,such as velocities and thicknesses.Velocity and thickness were found to be related to the strain signal patterns,curve fitting equations and I-kaz coefficients.The equations developed using this method had R2 values greater than 97.7%.Finally,the constructed equations were determined to be suitable for evaluating Charpy impact strain signal patterns and obtaining additional information on fracture processes under impact loading.
基金financially supported by the China Scholarship Council (CSC)(No. 201606080014)the University of Wollongong(UOW)the Electron Microscopy center of UOW (EMC)
文摘An equiatomic CoCrFeNiMn High Entropy Alloy(HEA)was in-situ deposited by the powder-bed arc ad-ditive manufacturing(PBAAM)process for the first time.Comparative research was conducted on the evolution of phase,crystallographic orientation,dislocation morphology,precipitation,and mechanical performance with the accumulation of inter-layer remelting times.The experimental outcomes mani-fested that the PBAAMed CoCrFeNiMn HEA consists of a stable solid-solution FCC structure,with de-creased lattice parameter but slightly increased(full width at half maximum)FWHM as the accumulation of the inter-layer remelting.The{001}<100>cube texture with a weakened texture intensity was de-tected with an increment of inter-layer remelting frequency from once to 5 times,yet it was transformed into{011}<100>Goss texture with a further increase to 7 times.Additionally,the mean grain diameter distinctly decreased,while the volume fraction of(low angle grain boundaries)LAGBs and dislocation density remarkably added up as the accumulated inter-layer remelts.Predominant cellular substructure generated in all process conditions and could be easily differentiated by elemental segregation.Both theσand M 23 C 6 Cr-rich precipitates in nano-scale and submicron MnS precipitate were detected on the grain boundaries of the PBAAMed deposited components,with a rather sparse distribution.Speaking of mechanical performance,the YS,UTS,and hardening rate are generally increased while the UE is grad-ually decreased as increased inter-layer remelting times.The studied PBAAMed CoCrFeNiMn HEA pos-sesses comparable mechanical performances with the counterparts of laser-deposited and as-cast ones.The strengthening mechanisms of the studied material are predominantly the grain boundary strength-ening and dislocation strengthening.This investigation would be a valuable resource in the research field of fabricating HEA alloys with acceptable microstructure and properties using the PBAAM method.
文摘The EFVM (Vitoria Minas Railroad) is one of the main railways in Brazil. It transports freight trains of ore, 220 wagons each. These wagons have 2 boogies of 2 axles each and 32 metric tons on metre gauge. Elastic strains were measured on a special part of this railway due to these trains. The main load to evaluate stresses and strains was a G 16 Locomotive, a C-C kind from Vale, a Brazilian Company. The measurements were obtained by dynamic deflectometer installed on a main line of this railway, near Ipatinga, a city from Minas Gerais, one of Brazil states. This track was equipped to obtain stresses under an equal repeated static load A simulation of the stresses was made under critical strain by Ferrovia 1.0 software. It was also made an evaluation of unequal results from neighbor sleepers taking in comparison two equipped parts of this railway, one with compacted ballast and no compaction to the other. The results were strain limited, avoiding breakage or damage to the studied rails. This work analyses these measurements focusing on the improvement of track quality.
基金Henan Province health science and technology innovation talents training project(No.YXKC 2020047)
文摘Background:Due to the wide variety of morphology,size,and dynamics,selecting an optimal valve size and location poses great difficulty in percutaneous pulmonary valve implantation(PPVI).This study aimed to report our experience with in vitro bench testing using patient-specific three-dimensional(3D)-printed models for planning PPVI with the Venus P-valve.Methods:Patient-specific 3D soft models were generated using PolyJet printing with a compliant synthetic material in 15 patients scheduled to undergo PPVI between July 2018 and July 2020 in Central China Fuwai Hospital of Zhengzhou University.Results:3D model bench testing altered treatment strategy in all patients(100%).One patient was referred for surgery because testing revealed that even the largest Venus P-valve would not anchor properly.In the remaining 14 patients,valve size and/or implantation location was altered to avoid valve migration and/or compression coronary artery.In four patients,it was decided to change the point anchoring because of inverted cone-shaped right ventricular outflow tract(RVOT)(n=2)or risk of compression coronary artery(n=2).Concerning sizing,we found that an oversize of 2-5 mm suffices.Anchoring of the valve was dictated by the flaring of the in-and outflow portion in the pulmonary artery.PPVI was successful in all 14 patients(absence of valve migration,no coronary compression,and none-to-mild residual pulmonary regurgitation[PR]).The diameter of the Venus P-valve in the 3D simulation group was significantly smaller than that of the conventional planning group(36[2]vs.32[4],Z=-3.77,P<0.001).Conclusions:In vitro testing indicated no need to oversize the Venus P-valve to the degree recommended by the balloon-sizing technique,as 2-5 mm sufficed.
基金supported by the National Key R&D Program of China(2022YFC2503400)Major science and technology special plan project of Yunnan Province(202302AA310045)Yunnan Provincial Clinical Research Center for Cardiovascular Diseases(202102AA310002).
文摘Transcatheter edge-to-edge repair(TEER)of the mitral valve has emerged as a standard treatment for patients with severe degenerative mitral regurgitation at high or prohibitive surgical risk.The devices approved by the Food and Drug Administration including MitraClip(Abbott Vascular,California,USA)and PASCAL(Edwards Lifesciences,California,USA)cost over$33,000 in western countries.[1]This pricing presents a significant economic burden especially in developing countries,where TEER devices are typically not covered by health insurance.
基金supported by a grant from Yunnan Provincial Cardiovascular Disease Clinical Medical Center Project(FZX201906-01)。
文摘Mitral valve regurgitation(MR)is a common heart valve disease that affects>10%of the elderly population.Epidemiological data estimate that the number of MR patients has reached more than2.5 million in the USA,with an extremely low surgical intervention rate(<5%)[1].