For virtually realizing the graphic realism display of DXF machine parts, in AutoCAD2007 graphic drawing environment, an interactive experimental method was taken to realize the display of graphic in DXF, which was ta...For virtually realizing the graphic realism display of DXF machine parts, in AutoCAD2007 graphic drawing environment, an interactive experimental method was taken to realize the display of graphic in DXF, which was taken as the data-exchanged interface and source. Based on depth analysis of DXF data structure, take one drawing of DXF lathe turning rotational part asthe test piece. By VC＋＋6.0 programming, part＇s geometry information could be obtained. Through data processing, 3D data of the test piece could be generated, which is based on 2D data of DXF test piece. Then, OpenGL graphic processing technologies （light, material, texture, map, et al.） were applied on the 3D display of test piece from DXF files or program modules. Finally based on the test report, results of the system functions were shared to prove the realization of system design, and the feasibility of algorithms used. In the developed software, Machine Designers could get a full view of machine parts, and do some proper modifications. The study content and results of our work have some theory and practical significance on the application of program design in the practical projects.展开更多
The particle mixing was studied in a cylindrical stirred tank with elliptical dished bottom by experiments and simulations.The impeller types used were double helical ribbon(HR) + bottom HR,pitched blade ribbon + bott...The particle mixing was studied in a cylindrical stirred tank with elliptical dished bottom by experiments and simulations.The impeller types used were double helical ribbon(HR) + bottom HR,pitched blade ribbon + bottom HR,inner and outer HR + bottom HR,and pitched blade ribbon + Pfaudler + bottom HR labeled as impellers Ⅰ to Ⅳ,respectively.The quantitative correlations among the rotational speed,fill level and power consumption for impeller Ⅰ and impeller Ⅱ were obtained by experiments to validate the discrete element method(DEM) simulations.The particle mixing at different operating conditions was simulated via DEM simulations to calculate the mixing index using the Lacey method,which is a statistical method to provide a mathematical understanding of the mixing state in a binary mixture.The simulation results reveal that as the rotational speed increases,the final mixing index increases,and as the fill level increases,the final mixing index decreases.At the same operating conditions,impeller Ⅲ is the optimal combination,which provides the highest mixing index at the same revolutions.展开更多
The rotational motions of the optically trapped microscopic particles by the vortex femtosecond laser beam are investigated in this paper.Black particles can be trapped and rotated by a vortex femtosecond laser beam v...The rotational motions of the optically trapped microscopic particles by the vortex femtosecond laser beam are investigated in this paper.Black particles can be trapped and rotated by a vortex femtosecond laser beam very effectively because the vortex beam carries orbital angular momentum due to the helical wave-front structure in assoication with the central phase singularity.Trapped black particles rotate in the vortex beam due to the absorption of the angular momentum transferred from the vortex beam.The rotating directions of the trapped particles can be modulated by reversing the topological charge of the optical vortex in the vortex femtosecond beam.And the rotating speeds of the trapped microscopic particles greatly depend on the topological charges of the vortex tweezer and the used pulse energies.展开更多
This study investigates the effect of tool rotational speed(TRS)on particle distribution in nugget zone(NZ)through quantitative approach and its consequences on the mechanical property of friction stir welded joints o...This study investigates the effect of tool rotational speed(TRS)on particle distribution in nugget zone(NZ)through quantitative approach and its consequences on the mechanical property of friction stir welded joints of AA6092/17.5 SiCp-T6 composite.6 mm thick plates are welded at a constant tool tilt angle of 2°and tool traverse speed of 1 mm/s by varying the TRS at 1000 rpm,1500 rpm and 2000 rpm with a taper pin profiled tool.Microstructure analysis shows large quantity of uniformly shaped smaller size SiC particle with lower average particle area which are homogeneously distributed in the NZ.The fragmentation of bigger size particles has been observed because of abrading action of the hard tool and resulting shearing effect and severe stress generation due to the rotation of tool.The particles occupy maximum area in the matrix compared to that of the base material(BM)due to the redistribution of broken particles as an effect of TRS.The migration of particles towards the TMAZ-NZ transition zone has been also encountered at higher TRS(2000 rpm).The microhardness analysis depicts variation in average hardness from top to bottom of the NZ,minimum for 1500 rpm and maximum for 2000 rpm.The impact strength at 1000 rpm and 1500 rpm remains close to that of BM(21.6 J)while 2000 rpm shows the accountable reduction.The maximum joint efficiency has been achieved at 1500 rpm(84%)and minimum at 1000 rpm(68%)under tensile loading.Fractographic analysis shows mixed mode of failure for BM,1000 rpm and 1500 rpm,whereas 2000 rpm shows the brittle mode of failure.展开更多
Rotational manipulation of massive particles and biolo gical samples is essential for the development of miniaturized lab-on-a-chip platforms in the fields of chemical,medical,and biological applications.In this paper...Rotational manipulation of massive particles and biolo gical samples is essential for the development of miniaturized lab-on-a-chip platforms in the fields of chemical,medical,and biological applications.In this paper,a device concept of a two-dimensional acoustofluidic chamber actuated by multiple nonlinear vibration sources is proposed.The functional chamber enables the generation of acoustic streaming vortices for potential applications that include strong mixing of multiphase flows and rotational manipulation of micro-/nano-scale objects without any rotating component.Using numerical simulations,we find that diversified acoustofluidic fields can be generated in the chamber under various actuations,and massive polystyrene beads inside can experience different acoustophoretic motions under the combined effect of an acoustic radiation force and acoustic streaming.Moreover,we investigate and clarify the effects of structural design on modulation of the acoustofluidic fields in the chamber.We believe the presented study could not only provide a promising potential tool for rotational acoustofluidic manipulation,but could also bring this community some useful design insights into the achievement of desired acoustofluidic fields for assorted microfluidic applications.展开更多
Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind ene...Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind energy applications.In industries,rotational bodies are commonly present in operations,yet this kinetic energy remains untapped.This research explores the energy generation characteristics of two rotational body types,disk-shaped and cylinder-shaped under specific experimental setups.The hardware setup included a direct current(DC)motor driver,power supply,DC generator,mechanical support,and load resistance,while the software setup involved automation testing tools and data logging.Electromagnetic induction was used to harvest energy,and experiments were conducted at room temperature(25℃)with controlled variables like speed and friction.Results showed the disk-shaped body exhibited higher energy efficiency than the cylinder-shaped body,largely due to lower mechanical losses.The disk required only two bearings,while the cylinder required four,resulting in lower bearing losses for the disk.Additionally,the disk experienced only air friction,whereas the cylinder encountered friction from a soft,uneven rubber material,increasing surface contact losses.Under a 40 W resistive load,the disk demonstrated a 17.1%energy loss due to mechanical friction,achieving up to 15.55 J of recycled energy.Conversely,the cylinder body experienced a 48.05%energy loss,delivering only 51.95%of energy to the load.These insights suggest significant potential for designing efficient energy recycling systems in industrial settings,particularly in manufacturing and processing industries where rotational machinery is prevalent.Despite its lower energy density,this system could be beneficially integrated with energy storage solutions,enhancing sustainability in industrial practices.展开更多
The drag and lift forces acting on a rotational spherical particle in a logarithmic boundary flow are numerically studied. The effects of the drag velocity and rotational speed of the sphere on the drag force are exam...The drag and lift forces acting on a rotational spherical particle in a logarithmic boundary flow are numerically studied. The effects of the drag velocity and rotational speed of the sphere on the drag force are examined for the particle Reynolds number from 50 to 300 and for the dimensionless rotational angular speed of 0≤Ω≤1.0. The influence of dimensionless roughness height Z0 of the wall is also evaluated for z0 ≤ 10. The results show that the drag forces on a sphere both in a logarithmic flow and in a uniform unsheared flow increase with the increase of the drag velocity. For 50≤Rep≤300, -↑CD increases with decreased roughness height z0. The time-averaged drag coefficient is also significantly affected by rotational speed of the sphere and roughness height zo. The lift coefficient -↑CL increases with increased rotational speed and decreases with increased roughness height.展开更多
In order to solve the problem of tension fluctuation overshoot of battery pole piece caused by the large moment of inertia of preheating roller, a tension control method based on magnetic particle clutch was proposed....In order to solve the problem of tension fluctuation overshoot of battery pole piece caused by the large moment of inertia of preheating roller, a tension control method based on magnetic particle clutch was proposed. A magnetic powder clutch driven by a servo motor is additionally arranged at the end of the preheating roller, and the speed of the servo motor is adjusted according to the principle of relative movement, so that the preheating roller can actively accelerate and decelerate according to the requirement of tension control, the negative influence of the inertia of the preheating roller on the tension control system is reduced, the tension fluctuation of the system is reduced, and the probability of occurrence of polar segment belts is finally reduced.展开更多
This letter compares the clinical efficacy and economic feasibility of the scoliocorrector fatma-UI(SCFUI)with direct vertebral rotation(DVR)in treating adolescent idiopathic scoliosis(AIS).SCFUI has shown promising r...This letter compares the clinical efficacy and economic feasibility of the scoliocorrector fatma-UI(SCFUI)with direct vertebral rotation(DVR)in treating adolescent idiopathic scoliosis(AIS).SCFUI has shown promising results in threedimensional spinal correction,providing superior rotational alignment compared to DVR and achieving significant improvements in coronal and sagittal planes.Additionally,SCFUI’s advanced design reduces risks associated with AIS surgeries and enhances overall patient outcomes.Economic analysis reveals SCFUI as a cost-effective option,potentially lowering long-term healthcare costs by minimizing complications and revisions.Our findings suggest that SCFUI is a viable,innovative approach in AIS treatment,meeting clinical and economic demands in orthopedic care.展开更多
Management of patients with acute hemorrhage requires addressing the source of bleeding,replenishing blood volume,and addressing any coagulopathy that may be present.Assessing coagulopathy and predicting blood require...Management of patients with acute hemorrhage requires addressing the source of bleeding,replenishing blood volume,and addressing any coagulopathy that may be present.Assessing coagulopathy and predicting blood requirements in real-time in patients experiencing ongoing bleeding can pose substantial challenges.In these patients,transfusion concepts based on ratios do not effectively address coagulopathy or reduce mortality.Moreover,ratio-based concepts do not stop bleeding;instead,they just give physicians more time to identify the bleeding source and plan management strategies.In clinical practice,standard laboratory coagulation tests(SLCT)are frequently used to assess various aspects of blood clotting.However,these tests may not always offer a comprehensive under-standing of clinically significant coagulopathy and the severity of blood loss.Furthermore,the SLCT have a considerable turnaround time,which may not be ideal for making prompt clinical decisions.In recent years,there has been a growing interest in point-of-care viscoelastic assays like rotational thromboelast-ometry,which provide real-time,dynamic information about clot formation and dissolution.展开更多
Industrial processes often involve rotating machinery that generates substantial kinetic energy,much of which remains untapped.Harvesting rotational kinetic energy offers a promising solution to reduce energy waste an...Industrial processes often involve rotating machinery that generates substantial kinetic energy,much of which remains untapped.Harvesting rotational kinetic energy offers a promising solution to reduce energy waste and improve energy efficiency in industrial applications.This research investigates the potential of electromagnetic induction for harvesting rotational kinetic energy from industrial machinery.A comparative study was conducted between disk and cylinder-shaped rotational bodies to evaluate their energy efficiency under various load conditions.Experimental results demonstrated that the disk body exhibited higher energy efficiency,primarily due to lower mechanical losses compared to the cylinder body.A power management circuit was developed to regulate and store the harvested energy,integrating voltage,current,and speed sensors along with a charge controller for battery storage.The experimental setup successfully converted rotational kinetic energy into usable electrical power,with the disk achieving up to 16.33 J of recycled energy,outperforming the cylinder.The disk body demonstrated higher energy recovery efficiency compared to the cylinder,particularly under the 40 W resistive load condition.These findings demonstrate the feasibility of implementing energy recycling systems in industrial settings to enhance sustainability,reduce energy consumption,and minimize waste.Future research should focus on optimizing power management systems and improving energy harvesting efficiency to enable wider adoption of energy recycling technologies in various industrial applications.展开更多
This study investigates the nonlinear dynamic properties of rotating functionally graded sandwich rectangular plates in a thermal environment.The nonlinear vibration equations for a rotating metal-ceramic functionally...This study investigates the nonlinear dynamic properties of rotating functionally graded sandwich rectangular plates in a thermal environment.The nonlinear vibration equations for a rotating metal-ceramic functionally graded sandwich rectangular plate in a thermal environment are derived using classical thin plate theory and Hamilton’s principle,considering geometric nonlinearity,temperature-dependent material properties,and power law distribution of components through the thickness.With cantilever boundary conditions,the flexural nonlinear differential equations of the rectangular sandwich plate are obtained via the Galerkin method.Since the natural vibration differential equations exhibit nonlinear characteristics,the multiscale method is employed to derive the expression for nonlinear natural frequency.An example analysis reveals how the natural frequency of a functionally graded sandwich rectangular plate varies with rotational speed and temperature.Results show that the nonlinear/linear frequency ratio increases with rotational angular velocity Ω and thickness-to-length ratio h/a,follows a cosine-like periodic pattern with the setting angle,and shows a sharp decrease followed by a rapid increase with increasing width-to-length ratio b/a.The derived analytical solutions for nonlinear frequency provide valuable insights for assessing the dynamic characteristics of functionally graded structures.展开更多
Rotational feeding combined with shift feeding electrochemical trepanning(RF-SF ECTr)is an effective method for machining aeroengine blisks.However,given the variable relative motion of the electrodes and the complex ...Rotational feeding combined with shift feeding electrochemical trepanning(RF-SF ECTr)is an effective method for machining aeroengine blisks.However,given the variable relative motion of the electrodes and the complex flow channels around the bending and twisting blades,the accessibility and uniformity of the flow field are poor in blisk RF-SF ECTr using the traditional electrolyte supply(TES)mode,resulting in poor machining stability and low machining efficiency.To improve the distribution of the flow field,a new multi-channel electrolyte supply(MCES)mode is proposed for blisk RF-SF ECTr,in which the position and volume of the electrolyte supply are controlled effectively by setting multiple inlet channels in the liquid inlet area.A flow-field simulation comparison between TES and MCES shows that better accessibility and uniformity of the flow-field distribution are achieved under MCES.To clarify further the flow-field distribution characteristics under RF-SF ECTr,a series of flow-field simulations was conducted at different machining depths.Based on the obtained dynamic change law for the flow field,to enhance further its uniformity and accessibility,a global coverage strategy for the electrolyte supply and a flow-field structure optimization method for MCES are proposed,which involve optimizing the number,diameter,and location of the inlet channels.After many simulations,the optimal MCES structure was achieved whereby the electrolyte covers all positions effectively in the processing area.To verify the proposed method as effective and correct,a series of RF-SF ECTr experiments was carried out.Under the optimized MCES mode,the feeding rate was increased from 0.8 mm/min with the TES mode to 2.0 mm/min,and the processing stability and efficiency were improved significantly.The methods presented here offer an effective guide for flow-field optimization when machining other components with complex spatial structures.展开更多
We study the motion of an inertial microswimmer in a non-Newtonian environment with a finite memory and present the theoretical realization of an unexpected transition from random self-propulsion to rotational(circula...We study the motion of an inertial microswimmer in a non-Newtonian environment with a finite memory and present the theoretical realization of an unexpected transition from random self-propulsion to rotational(circular or elliptical)motion.Further,the rotational motion of the swimmer is followed by spontaneous local directional reversal,yet with a steady-state angular diffusion.Moreover,the advent of this behaviour is observed in the oscillatory regime of the inertia-memory parameter space of the dynamics.We quantify this unconventional rotational motion of the microswimmer by measuring the time evolution of the direction of its instantaneous velocity or orientation.By solving the generalized Langevin model of non-Markovian dynamics of an inertial active Ornstein–Uhlenbeck particle,we show that the emergence of the rotational(circular or elliptical)trajectory is due to the presence of both inertial motion and memory in the environment.展开更多
Scaffolds that emulate the architecture of human bone,combined with strong mechanical stability and biocompatibility,are vital for promoting effective bone tissue regeneration.However,most existing bone-mimetic scaffo...Scaffolds that emulate the architecture of human bone,combined with strong mechanical stability and biocompatibility,are vital for promoting effective bone tissue regeneration.However,most existing bone-mimetic scaffolds fall short in reproducing the intricate hierarchical structure of human bone,which restricts their practical application.This study introduces a novel strategy that combines rotational three-dimensional(3D)printing technology and sponge replication technique to fabricate bone-mimetic scaffolds based on composite materials comprising copper-substituted diopside and biphasic calcium phosphate.The scaffolds closely mimic the structure of human bone,featuring both cancellous and cortical bone with Haversian canals.Additionally,the scaffolds exhibit high porosity and transport capacity,while exhibiting compressive strength that is on par with human bone under both axial and lateral loads.Moreover,they demonstrate good biocompatibility and the potential to induce and support osteogenesis and angiogenesis.The scaffolds produced here present a pathway to remediating particularly large bone defects.Given their close resemblance to human bone structure and function,these scaffolds may be well-suited for developing in vitro bone disease models for pharmaceutical testing and various biomedical applications.展开更多
The low-altitude transport has demonstrated significant growth potential driven by rapid advancements in unmanned aerial vehicles(UAVs)technology.Herein,rotor UAVs are increasingly favored by consumers due to their un...The low-altitude transport has demonstrated significant growth potential driven by rapid advancements in unmanned aerial vehicles(UAVs)technology.Herein,rotor UAVs are increasingly favored by consumers due to their unique advantages.The UAVs motion is altered by adjusting propeller speed,which is governed by motor speed.Consequently,motor speed is a key factor influencing flight performance that is susceptible to environmental interference.Accurate and real-time monitoring of motor speed is essential.Conventional speed sensors are bulky,reliant on external power,and challenging to integration into compact UAVs systems.They also suffer from insufficient accuracy and unstable measurements,particularly with small motors.This article introduces a self-powered digital aircraft rotational speed sensor(SDARSS)utilizing a rotating triboelectric nanogenerators(TENGs)to address current challenges.This sensor is lightweight,energy-efficient,and self-powered,weighing only 2.185 g and measuring 3.43 mm in thickness,with an accuracy exceeding 99.94%.It measures speeds up to 10,000 revolutions per minute(rpm)with exceptional precision and stability.The sensor enables real-time monitoring of UAVs motor speeds,which is crucial for enhancing flight safety.展开更多
The vibration analysis of Kirchhoff plates requires robust mass lumping schemes to guarantee numerical stability and accuracy.However,existing methods fail to generate symmetric and positive definite mass matrices whe...The vibration analysis of Kirchhoff plates requires robust mass lumping schemes to guarantee numerical stability and accuracy.However,existing methods fail to generate symmetric and positive definite mass matrices when handling rotational degrees of freedom,leading to compromised performance in both time and frequency domains analyses.This study proposes a manifold-based mass lumping scheme that systematically resolves the inertia matrix formulas for rotational/torsional degrees of freedom.By reinterpreting the finite element mesh as a mathematical cover composed of overlapping patches,Hermitian interpolations for plate deflection are derived using partition of unity principles.The manifold-based mass matrix is constructed by integrating the virtual work of inertia forces over these patches,ensuring symmetry and positive definiteness.Numerical benchmarks demonstrate that the manifold-based mass lumping scheme performance can be comparable or better than the consistent mass scheme and other existing mass lumping schemes.This work establishes a unified theory for mass lumping in fourth order plate dynamics,proving that the widely used row-sum method is a special case of the manifold-based framework.The scheme resolves long-standing limitations in rotational/torsional inertia conservation and provides a foundation for extending rigorous mass lumping to 3D shell and nonlinear dynamic analyses.展开更多
This study conducted the experimental investigation of aerodynamic heating of Micro-scale Rotational Shearing Flow with Axial Limited-Length(MRSFALL).The temperature riseof the stator is captured by the high response ...This study conducted the experimental investigation of aerodynamic heating of Micro-scale Rotational Shearing Flow with Axial Limited-Length(MRSFALL).The temperature riseof the stator is captured by the high response thermocouples.The eccentricity ratio and clearanceheight are guaranteed by means of instantaneous trajectory and torsion monitoring of the rotator.The result shows that the maximum temperature rise takes place upstream of the minimum clear-ance height along circumferential direction.The distribution of temperature rise presents asymmet-ric curve along axial direction,and peak value occurs near the dimensionless axial position of-0.18.The effect of aerodynamic heating becomes notable as the rotational speed is larger than3×10^(4)r/min.The effect of end leakage and the viscous dissipation have great impact on temper-ature rise of MRSFALL.More specially,the peak value of temperature rise at dimensionless clear-ance height of 0.0080 is larger than the case at dimensionless clearance height of 0.0044.Furthermore,when the eccentricity ratio is too large,the viscous dissipation is induced,and theadditional temperature rise is achieved.The heat flux identification of shear flow has been realizedby Sequential Function Specification Method(SFSM)and its estimation of thermal load has been given.The heat flux induced by the aerodynamic heating in this study varies from 950 W/m^(2)to1330 W/m^(2).展开更多
Rotational dynamics simulations of neutral O_(2)molecules driven by linearly,elliptically and circularly polarized femtosecond pulsed lasers are carried out using a full quantum time-dependent wave packet evolution me...Rotational dynamics simulations of neutral O_(2)molecules driven by linearly,elliptically and circularly polarized femtosecond pulsed lasers are carried out using a full quantum time-dependent wave packet evolution method.Here,the direction of laser propagation is set along the z axis,and the polarization plane is restricted to the xy plane.The results indicate that the alignment of O_(2)molecules in the z direction is weakly affected by varying the ellipticity when the total laser intensity is held constant.For rotation within the xy plane,the linearly polarized laser significantly excites rotational motion,with the degree of excitation increasing as the ellipticity increases.In contrast,under the influence of a circularly polarized laser,the angular distribution of O_(2)molecules in the xy plane remains isotropic.Additionally,the effects of the initial rotational quantum number,the temperature of the O_(2)molecules and the nuclear spin on laser-induced alignment are discussed.展开更多
Objective:To clarify the preferences and core demands of professional Master’s students in Tuina at Yunnan University of Chinese Medicine regarding“concentrated”versus“dispersed”rotation schedules in the Tuina de...Objective:To clarify the preferences and core demands of professional Master’s students in Tuina at Yunnan University of Chinese Medicine regarding“concentrated”versus“dispersed”rotation schedules in the Tuina department,as well as their preferred year for primary rotation,providing evidence for optimizing rotation programs and improving the quality of standardized training.Methods:Paper questionnaires,including two multiple-choice questions and one open-ended question,were distributed to 30 professional Tuina Master’s students,completed on site,and collected immediately.Descriptive statistics were used to analyze preference distributions.Results:A total of 30 questionnaires were distributed and 30 valid responses were collected,achieving a 100%response rate.Among them,23 students(76.7%)supported“concentrated training,”while seven students(23.3%)preferred“dispersed training.”Regarding rotation year preference,18 students(60.0%)selected the second year for concentrated Tuina rotations,eight students(26.7%)selected the third year,and four students(13.3%)selected the first year.The core demands supporting concentrated training were“skill continuity,deep involvement in diagnosis and treatment,and smooth mentorship transition,”whereas those supporting dispersed training were“integration of multi-department knowledge,coordination of research time,and avoidance of fatigue from a single department.”Conclusion:Most professional Tuina Master’s students prefer concentrated Tuina rotations in the second year.It is recommended that institutions adopt a“second-year core department concentrated+auxiliary department flexible dispersed”model and establish flexible coordination and feedback mechanisms to balance clinical skill development with individualized growth needs.展开更多
文摘For virtually realizing the graphic realism display of DXF machine parts, in AutoCAD2007 graphic drawing environment, an interactive experimental method was taken to realize the display of graphic in DXF, which was taken as the data-exchanged interface and source. Based on depth analysis of DXF data structure, take one drawing of DXF lathe turning rotational part asthe test piece. By VC＋＋6.0 programming, part＇s geometry information could be obtained. Through data processing, 3D data of the test piece could be generated, which is based on 2D data of DXF test piece. Then, OpenGL graphic processing technologies （light, material, texture, map, et al.） were applied on the 3D display of test piece from DXF files or program modules. Finally based on the test report, results of the system functions were shared to prove the realization of system design, and the feasibility of algorithms used. In the developed software, Machine Designers could get a full view of machine parts, and do some proper modifications. The study content and results of our work have some theory and practical significance on the application of program design in the practical projects.
文摘The particle mixing was studied in a cylindrical stirred tank with elliptical dished bottom by experiments and simulations.The impeller types used were double helical ribbon(HR) + bottom HR,pitched blade ribbon + bottom HR,inner and outer HR + bottom HR,and pitched blade ribbon + Pfaudler + bottom HR labeled as impellers Ⅰ to Ⅳ,respectively.The quantitative correlations among the rotational speed,fill level and power consumption for impeller Ⅰ and impeller Ⅱ were obtained by experiments to validate the discrete element method(DEM) simulations.The particle mixing at different operating conditions was simulated via DEM simulations to calculate the mixing index using the Lacey method,which is a statistical method to provide a mathematical understanding of the mixing state in a binary mixture.The simulation results reveal that as the rotational speed increases,the final mixing index increases,and as the fill level increases,the final mixing index decreases.At the same operating conditions,impeller Ⅲ is the optimal combination,which provides the highest mixing index at the same revolutions.
基金Project supported by the National Natural Science Foundation for Post-Doctoral Scientists of China (Grant No. 2012M511002)the National Natural Science Foundation of China (Grant Nos. 10904027 and 61108018)the Science and Technology Programs of Heilongjiang Educational Committee,China (Grant No. 12511425)
文摘The rotational motions of the optically trapped microscopic particles by the vortex femtosecond laser beam are investigated in this paper.Black particles can be trapped and rotated by a vortex femtosecond laser beam very effectively because the vortex beam carries orbital angular momentum due to the helical wave-front structure in assoication with the central phase singularity.Trapped black particles rotate in the vortex beam due to the absorption of the angular momentum transferred from the vortex beam.The rotating directions of the trapped particles can be modulated by reversing the topological charge of the optical vortex in the vortex femtosecond beam.And the rotating speeds of the trapped microscopic particles greatly depend on the topological charges of the vortex tweezer and the used pulse energies.
基金Ministry of Human Resource,Government of India for providing necessary funding through scholarship to carry out the research activities。
文摘This study investigates the effect of tool rotational speed(TRS)on particle distribution in nugget zone(NZ)through quantitative approach and its consequences on the mechanical property of friction stir welded joints of AA6092/17.5 SiCp-T6 composite.6 mm thick plates are welded at a constant tool tilt angle of 2°and tool traverse speed of 1 mm/s by varying the TRS at 1000 rpm,1500 rpm and 2000 rpm with a taper pin profiled tool.Microstructure analysis shows large quantity of uniformly shaped smaller size SiC particle with lower average particle area which are homogeneously distributed in the NZ.The fragmentation of bigger size particles has been observed because of abrading action of the hard tool and resulting shearing effect and severe stress generation due to the rotation of tool.The particles occupy maximum area in the matrix compared to that of the base material(BM)due to the redistribution of broken particles as an effect of TRS.The migration of particles towards the TMAZ-NZ transition zone has been also encountered at higher TRS(2000 rpm).The microhardness analysis depicts variation in average hardness from top to bottom of the NZ,minimum for 1500 rpm and maximum for 2000 rpm.The impact strength at 1000 rpm and 1500 rpm remains close to that of BM(21.6 J)while 2000 rpm shows the accountable reduction.The maximum joint efficiency has been achieved at 1500 rpm(84%)and minimum at 1000 rpm(68%)under tensile loading.Fractographic analysis shows mixed mode of failure for BM,1000 rpm and 1500 rpm,whereas 2000 rpm shows the brittle mode of failure.
基金Project supported by the National Natural Science Foundation of China(Grant No.11904117)the IndustryUniversity-Research Collaboration Project of Jiangsu Province,China(Grant No.BY2019058)+1 种基金the Scientific Research Foundation of Huaiyin Institute of Technology(Grant No.Z301B19529)the Training Foundation of Postgraduate Supervisor(Grant No.Z206E20555)。
文摘Rotational manipulation of massive particles and biolo gical samples is essential for the development of miniaturized lab-on-a-chip platforms in the fields of chemical,medical,and biological applications.In this paper,a device concept of a two-dimensional acoustofluidic chamber actuated by multiple nonlinear vibration sources is proposed.The functional chamber enables the generation of acoustic streaming vortices for potential applications that include strong mixing of multiphase flows and rotational manipulation of micro-/nano-scale objects without any rotating component.Using numerical simulations,we find that diversified acoustofluidic fields can be generated in the chamber under various actuations,and massive polystyrene beads inside can experience different acoustophoretic motions under the combined effect of an acoustic radiation force and acoustic streaming.Moreover,we investigate and clarify the effects of structural design on modulation of the acoustofluidic fields in the chamber.We believe the presented study could not only provide a promising potential tool for rotational acoustofluidic manipulation,but could also bring this community some useful design insights into the achievement of desired acoustofluidic fields for assorted microfluidic applications.
基金The APC was funded by Research Management Center, Multimedia University, Malaysia.
文摘Electrical energy can be harvested from the rotational kinetic energy of moving bodies,consisting of both mechanical and kinetic energy as a potential power source through electromagnetic induction,similar to wind energy applications.In industries,rotational bodies are commonly present in operations,yet this kinetic energy remains untapped.This research explores the energy generation characteristics of two rotational body types,disk-shaped and cylinder-shaped under specific experimental setups.The hardware setup included a direct current(DC)motor driver,power supply,DC generator,mechanical support,and load resistance,while the software setup involved automation testing tools and data logging.Electromagnetic induction was used to harvest energy,and experiments were conducted at room temperature(25℃)with controlled variables like speed and friction.Results showed the disk-shaped body exhibited higher energy efficiency than the cylinder-shaped body,largely due to lower mechanical losses.The disk required only two bearings,while the cylinder required four,resulting in lower bearing losses for the disk.Additionally,the disk experienced only air friction,whereas the cylinder encountered friction from a soft,uneven rubber material,increasing surface contact losses.Under a 40 W resistive load,the disk demonstrated a 17.1%energy loss due to mechanical friction,achieving up to 15.55 J of recycled energy.Conversely,the cylinder body experienced a 48.05%energy loss,delivering only 51.95%of energy to the load.These insights suggest significant potential for designing efficient energy recycling systems in industrial settings,particularly in manufacturing and processing industries where rotational machinery is prevalent.Despite its lower energy density,this system could be beneficially integrated with energy storage solutions,enhancing sustainability in industrial practices.
文摘The drag and lift forces acting on a rotational spherical particle in a logarithmic boundary flow are numerically studied. The effects of the drag velocity and rotational speed of the sphere on the drag force are examined for the particle Reynolds number from 50 to 300 and for the dimensionless rotational angular speed of 0≤Ω≤1.0. The influence of dimensionless roughness height Z0 of the wall is also evaluated for z0 ≤ 10. The results show that the drag forces on a sphere both in a logarithmic flow and in a uniform unsheared flow increase with the increase of the drag velocity. For 50≤Rep≤300, -↑CD increases with decreased roughness height z0. The time-averaged drag coefficient is also significantly affected by rotational speed of the sphere and roughness height zo. The lift coefficient -↑CL increases with increased rotational speed and decreases with increased roughness height.
文摘In order to solve the problem of tension fluctuation overshoot of battery pole piece caused by the large moment of inertia of preheating roller, a tension control method based on magnetic particle clutch was proposed. A magnetic powder clutch driven by a servo motor is additionally arranged at the end of the preheating roller, and the speed of the servo motor is adjusted according to the principle of relative movement, so that the preheating roller can actively accelerate and decelerate according to the requirement of tension control, the negative influence of the inertia of the preheating roller on the tension control system is reduced, the tension fluctuation of the system is reduced, and the probability of occurrence of polar segment belts is finally reduced.
文摘This letter compares the clinical efficacy and economic feasibility of the scoliocorrector fatma-UI(SCFUI)with direct vertebral rotation(DVR)in treating adolescent idiopathic scoliosis(AIS).SCFUI has shown promising results in threedimensional spinal correction,providing superior rotational alignment compared to DVR and achieving significant improvements in coronal and sagittal planes.Additionally,SCFUI’s advanced design reduces risks associated with AIS surgeries and enhances overall patient outcomes.Economic analysis reveals SCFUI as a cost-effective option,potentially lowering long-term healthcare costs by minimizing complications and revisions.Our findings suggest that SCFUI is a viable,innovative approach in AIS treatment,meeting clinical and economic demands in orthopedic care.
文摘Management of patients with acute hemorrhage requires addressing the source of bleeding,replenishing blood volume,and addressing any coagulopathy that may be present.Assessing coagulopathy and predicting blood requirements in real-time in patients experiencing ongoing bleeding can pose substantial challenges.In these patients,transfusion concepts based on ratios do not effectively address coagulopathy or reduce mortality.Moreover,ratio-based concepts do not stop bleeding;instead,they just give physicians more time to identify the bleeding source and plan management strategies.In clinical practice,standard laboratory coagulation tests(SLCT)are frequently used to assess various aspects of blood clotting.However,these tests may not always offer a comprehensive under-standing of clinically significant coagulopathy and the severity of blood loss.Furthermore,the SLCT have a considerable turnaround time,which may not be ideal for making prompt clinical decisions.In recent years,there has been a growing interest in point-of-care viscoelastic assays like rotational thromboelast-ometry,which provide real-time,dynamic information about clot formation and dissolution.
文摘Industrial processes often involve rotating machinery that generates substantial kinetic energy,much of which remains untapped.Harvesting rotational kinetic energy offers a promising solution to reduce energy waste and improve energy efficiency in industrial applications.This research investigates the potential of electromagnetic induction for harvesting rotational kinetic energy from industrial machinery.A comparative study was conducted between disk and cylinder-shaped rotational bodies to evaluate their energy efficiency under various load conditions.Experimental results demonstrated that the disk body exhibited higher energy efficiency,primarily due to lower mechanical losses compared to the cylinder body.A power management circuit was developed to regulate and store the harvested energy,integrating voltage,current,and speed sensors along with a charge controller for battery storage.The experimental setup successfully converted rotational kinetic energy into usable electrical power,with the disk achieving up to 16.33 J of recycled energy,outperforming the cylinder.The disk body demonstrated higher energy recovery efficiency compared to the cylinder,particularly under the 40 W resistive load condition.These findings demonstrate the feasibility of implementing energy recycling systems in industrial settings to enhance sustainability,reduce energy consumption,and minimize waste.Future research should focus on optimizing power management systems and improving energy harvesting efficiency to enable wider adoption of energy recycling technologies in various industrial applications.
基金supported by the National Natural Science Foundation of China(No.11772090).
文摘This study investigates the nonlinear dynamic properties of rotating functionally graded sandwich rectangular plates in a thermal environment.The nonlinear vibration equations for a rotating metal-ceramic functionally graded sandwich rectangular plate in a thermal environment are derived using classical thin plate theory and Hamilton’s principle,considering geometric nonlinearity,temperature-dependent material properties,and power law distribution of components through the thickness.With cantilever boundary conditions,the flexural nonlinear differential equations of the rectangular sandwich plate are obtained via the Galerkin method.Since the natural vibration differential equations exhibit nonlinear characteristics,the multiscale method is employed to derive the expression for nonlinear natural frequency.An example analysis reveals how the natural frequency of a functionally graded sandwich rectangular plate varies with rotational speed and temperature.Results show that the nonlinear/linear frequency ratio increases with rotational angular velocity Ω and thickness-to-length ratio h/a,follows a cosine-like periodic pattern with the setting angle,and shows a sharp decrease followed by a rapid increase with increasing width-to-length ratio b/a.The derived analytical solutions for nonlinear frequency provide valuable insights for assessing the dynamic characteristics of functionally graded structures.
基金Supported by National Natural Science Foundation of China(Grant Nos.52275435,52075465,52375519)Open Fund Project of Jiangsu Key Laboratory of Precision and Micro-manufacturing Technology(Grant No.JSKL2324K03)Key Research and Development Program of Hunan Province of China(Grant No.2023GK2026)。
文摘Rotational feeding combined with shift feeding electrochemical trepanning(RF-SF ECTr)is an effective method for machining aeroengine blisks.However,given the variable relative motion of the electrodes and the complex flow channels around the bending and twisting blades,the accessibility and uniformity of the flow field are poor in blisk RF-SF ECTr using the traditional electrolyte supply(TES)mode,resulting in poor machining stability and low machining efficiency.To improve the distribution of the flow field,a new multi-channel electrolyte supply(MCES)mode is proposed for blisk RF-SF ECTr,in which the position and volume of the electrolyte supply are controlled effectively by setting multiple inlet channels in the liquid inlet area.A flow-field simulation comparison between TES and MCES shows that better accessibility and uniformity of the flow-field distribution are achieved under MCES.To clarify further the flow-field distribution characteristics under RF-SF ECTr,a series of flow-field simulations was conducted at different machining depths.Based on the obtained dynamic change law for the flow field,to enhance further its uniformity and accessibility,a global coverage strategy for the electrolyte supply and a flow-field structure optimization method for MCES are proposed,which involve optimizing the number,diameter,and location of the inlet channels.After many simulations,the optimal MCES structure was achieved whereby the electrolyte covers all positions effectively in the processing area.To verify the proposed method as effective and correct,a series of RF-SF ECTr experiments was carried out.Under the optimized MCES mode,the feeding rate was increased from 0.8 mm/min with the TES mode to 2.0 mm/min,and the processing stability and efficiency were improved significantly.The methods presented here offer an effective guide for flow-field optimization when machining other components with complex spatial structures.
基金the 8th Statphysics Community Meeting(ICTS/ISPCM2023/02)during which we had lots of fruitful discussionsMS acknowledges the start-up grant from UGC,SERB-SURE grant(SUR/2022/000377),CRG grant(CRG/2023/002026)from DST,Govt.of India for the financial support。
文摘We study the motion of an inertial microswimmer in a non-Newtonian environment with a finite memory and present the theoretical realization of an unexpected transition from random self-propulsion to rotational(circular or elliptical)motion.Further,the rotational motion of the swimmer is followed by spontaneous local directional reversal,yet with a steady-state angular diffusion.Moreover,the advent of this behaviour is observed in the oscillatory regime of the inertia-memory parameter space of the dynamics.We quantify this unconventional rotational motion of the microswimmer by measuring the time evolution of the direction of its instantaneous velocity or orientation.By solving the generalized Langevin model of non-Markovian dynamics of an inertial active Ornstein–Uhlenbeck particle,we show that the emergence of the rotational(circular or elliptical)trajectory is due to the presence of both inertial motion and memory in the environment.
文摘Scaffolds that emulate the architecture of human bone,combined with strong mechanical stability and biocompatibility,are vital for promoting effective bone tissue regeneration.However,most existing bone-mimetic scaffolds fall short in reproducing the intricate hierarchical structure of human bone,which restricts their practical application.This study introduces a novel strategy that combines rotational three-dimensional(3D)printing technology and sponge replication technique to fabricate bone-mimetic scaffolds based on composite materials comprising copper-substituted diopside and biphasic calcium phosphate.The scaffolds closely mimic the structure of human bone,featuring both cancellous and cortical bone with Haversian canals.Additionally,the scaffolds exhibit high porosity and transport capacity,while exhibiting compressive strength that is on par with human bone under both axial and lateral loads.Moreover,they demonstrate good biocompatibility and the potential to induce and support osteogenesis and angiogenesis.The scaffolds produced here present a pathway to remediating particularly large bone defects.Given their close resemblance to human bone structure and function,these scaffolds may be well-suited for developing in vitro bone disease models for pharmaceutical testing and various biomedical applications.
基金supported by the National Natural Science Foundation of China(No.52203324)the National Key R&D Program of China(No.2023YFB2604600)+1 种基金the National Key R&D Project from the Minister of Science and Technology(No.2021YFA1201601)Thanks to the Georgia Institute of Technology for providing software support。
文摘The low-altitude transport has demonstrated significant growth potential driven by rapid advancements in unmanned aerial vehicles(UAVs)technology.Herein,rotor UAVs are increasingly favored by consumers due to their unique advantages.The UAVs motion is altered by adjusting propeller speed,which is governed by motor speed.Consequently,motor speed is a key factor influencing flight performance that is susceptible to environmental interference.Accurate and real-time monitoring of motor speed is essential.Conventional speed sensors are bulky,reliant on external power,and challenging to integration into compact UAVs systems.They also suffer from insufficient accuracy and unstable measurements,particularly with small motors.This article introduces a self-powered digital aircraft rotational speed sensor(SDARSS)utilizing a rotating triboelectric nanogenerators(TENGs)to address current challenges.This sensor is lightweight,energy-efficient,and self-powered,weighing only 2.185 g and measuring 3.43 mm in thickness,with an accuracy exceeding 99.94%.It measures speeds up to 10,000 revolutions per minute(rpm)with exceptional precision and stability.The sensor enables real-time monitoring of UAVs motor speeds,which is crucial for enhancing flight safety.
基金supported by National Natural Science Foundation of China(Grant Nos.42107214 and 52130905)the Natural Science Foundation of Chongqing(No.CSTB2024NSCQMSX0740)the Henan Province Science and Technology Research Projects(No.252102220050).
文摘The vibration analysis of Kirchhoff plates requires robust mass lumping schemes to guarantee numerical stability and accuracy.However,existing methods fail to generate symmetric and positive definite mass matrices when handling rotational degrees of freedom,leading to compromised performance in both time and frequency domains analyses.This study proposes a manifold-based mass lumping scheme that systematically resolves the inertia matrix formulas for rotational/torsional degrees of freedom.By reinterpreting the finite element mesh as a mathematical cover composed of overlapping patches,Hermitian interpolations for plate deflection are derived using partition of unity principles.The manifold-based mass matrix is constructed by integrating the virtual work of inertia forces over these patches,ensuring symmetry and positive definiteness.Numerical benchmarks demonstrate that the manifold-based mass lumping scheme performance can be comparable or better than the consistent mass scheme and other existing mass lumping schemes.This work establishes a unified theory for mass lumping in fourth order plate dynamics,proving that the widely used row-sum method is a special case of the manifold-based framework.The scheme resolves long-standing limitations in rotational/torsional inertia conservation and provides a foundation for extending rigorous mass lumping to 3D shell and nonlinear dynamic analyses.
基金supports from the National Natural Science Foundation of China(No.52206091)the Aeronautical Science Foundation of China(No.201928052008)the Natural Science Foundation of Jiangsu Province,China(No.BK20210303)。
文摘This study conducted the experimental investigation of aerodynamic heating of Micro-scale Rotational Shearing Flow with Axial Limited-Length(MRSFALL).The temperature riseof the stator is captured by the high response thermocouples.The eccentricity ratio and clearanceheight are guaranteed by means of instantaneous trajectory and torsion monitoring of the rotator.The result shows that the maximum temperature rise takes place upstream of the minimum clear-ance height along circumferential direction.The distribution of temperature rise presents asymmet-ric curve along axial direction,and peak value occurs near the dimensionless axial position of-0.18.The effect of aerodynamic heating becomes notable as the rotational speed is larger than3×10^(4)r/min.The effect of end leakage and the viscous dissipation have great impact on temper-ature rise of MRSFALL.More specially,the peak value of temperature rise at dimensionless clear-ance height of 0.0080 is larger than the case at dimensionless clearance height of 0.0044.Furthermore,when the eccentricity ratio is too large,the viscous dissipation is induced,and theadditional temperature rise is achieved.The heat flux identification of shear flow has been realizedby Sequential Function Specification Method(SFSM)and its estimation of thermal load has been given.The heat flux induced by the aerodynamic heating in this study varies from 950 W/m^(2)to1330 W/m^(2).
基金supported by the National Key Research and Development Program of China(Grant No.2022YFA1602502)the National Natural Science Foundation of China(Grant No.12450404).
文摘Rotational dynamics simulations of neutral O_(2)molecules driven by linearly,elliptically and circularly polarized femtosecond pulsed lasers are carried out using a full quantum time-dependent wave packet evolution method.Here,the direction of laser propagation is set along the z axis,and the polarization plane is restricted to the xy plane.The results indicate that the alignment of O_(2)molecules in the z direction is weakly affected by varying the ellipticity when the total laser intensity is held constant.For rotation within the xy plane,the linearly polarized laser significantly excites rotational motion,with the degree of excitation increasing as the ellipticity increases.In contrast,under the influence of a circularly polarized laser,the angular distribution of O_(2)molecules in the xy plane remains isotropic.Additionally,the effects of the initial rotational quantum number,the temperature of the O_(2)molecules and the nuclear spin on laser-induced alignment are discussed.
文摘Objective:To clarify the preferences and core demands of professional Master’s students in Tuina at Yunnan University of Chinese Medicine regarding“concentrated”versus“dispersed”rotation schedules in the Tuina department,as well as their preferred year for primary rotation,providing evidence for optimizing rotation programs and improving the quality of standardized training.Methods:Paper questionnaires,including two multiple-choice questions and one open-ended question,were distributed to 30 professional Tuina Master’s students,completed on site,and collected immediately.Descriptive statistics were used to analyze preference distributions.Results:A total of 30 questionnaires were distributed and 30 valid responses were collected,achieving a 100%response rate.Among them,23 students(76.7%)supported“concentrated training,”while seven students(23.3%)preferred“dispersed training.”Regarding rotation year preference,18 students(60.0%)selected the second year for concentrated Tuina rotations,eight students(26.7%)selected the third year,and four students(13.3%)selected the first year.The core demands supporting concentrated training were“skill continuity,deep involvement in diagnosis and treatment,and smooth mentorship transition,”whereas those supporting dispersed training were“integration of multi-department knowledge,coordination of research time,and avoidance of fatigue from a single department.”Conclusion:Most professional Tuina Master’s students prefer concentrated Tuina rotations in the second year.It is recommended that institutions adopt a“second-year core department concentrated+auxiliary department flexible dispersed”model and establish flexible coordination and feedback mechanisms to balance clinical skill development with individualized growth needs.
