This research paper introduces a soft VR glove that enhances how users interact with virtual objects. It seamlessly integrates discrete modules for sensing and providing haptic feedback, encompassing tactile and kinae...This research paper introduces a soft VR glove that enhances how users interact with virtual objects. It seamlessly integrates discrete modules for sensing and providing haptic feedback, encompassing tactile and kinaesthetic aspects while prioritizing wearability and natural finger movements. The glove employs custom-designed flexible bend sensors with carbon-impregnated film for in-situ joint angle tracking, simplifying the sensing system and enhancing portability. A multi-modal haptic feedback approach includes an innovative pneumatically actuated tactile feedback technique and a motor-tendon-driven kinaesthetic feedback system, providing exceptional realism in virtual object manipulation. The glove’s kinaesthetic feedback lets users perceive virtual objects’ size, shape, and stiffness characteristics. Psychophysical investigations demonstrate how readily the users acclimate to this hardware and prove each module’s effectiveness and synergistic operation. This soft VR glove represents a minimalist, lightweight, and comprehensive solution for authentic haptic interaction in virtual environments, opening new possibilities for applications in various fields.展开更多
A meticulous design of the local environment at the interface between active species and the support,aimed at optimizing the adsorption of H_(2)O molecules and BH_(4)^(-)anion,offers an ideal strategy for enhancing hy...A meticulous design of the local environment at the interface between active species and the support,aimed at optimizing the adsorption of H_(2)O molecules and BH_(4)^(-)anion,offers an ideal strategy for enhancing hydrogen generation via Na BH4hydrolysis through dual activation pathways.Theoretical predictions based on d-band center analysis and electron transfer calculations suggest that introducing-OH functional groups induce charge redistribution,enhancing charge concentration on alk-Ti_(3)C_(2)and facilitating the adsorption and activation of dual active species,H2O molecules and BH4-anion.Inspired by these predictions,the optimized alk-Ti_(3)C_(2)/Ru Oxcatalyst demonstrates the highest catalytic activity,achieving a hydrogen generation rate(HGR)of 9468 m L min^(-1)gcat.^(-1).Both experimental data and theoretical analyses confirm that the-OH functional groups promote charge enrichment on alk-Ti_(3)C_(2),optimizing the adsorption of H_(2)O molecules and BH_(4)^(-)anion,and reducing the dissociation energy barrier of the*OH–H-TS intermediate.This dual activation pathways mechanism lowers the activation energy for Na BH4hydrolysis,significantly enhancing the HGR performance.These findings,guided by theoretical insights,establish alk-Ti_(3)C_(2)/Ru Oxas an efficient catalyst for Na BH4hydrolysis and provide a strong foundation for future hydrogen generation catalyst designs.展开更多
Brain tumor segmentation from Magnetic Resonance Imaging(MRI)supports neurologists and radiologists in analyzing tumors and developing personalized treatment plans,making it a crucial yet challenging task.Supervised m...Brain tumor segmentation from Magnetic Resonance Imaging(MRI)supports neurologists and radiologists in analyzing tumors and developing personalized treatment plans,making it a crucial yet challenging task.Supervised models such as 3D U-Net perform well in this domain,but their accuracy significantly improves with appropriate preprocessing.This paper demonstrates the effectiveness of preprocessing in brain tumor segmentation by applying a pre-segmentation step based on the Generalized Gaussian Mixture Model(GGMM)to T1 contrastenhanced MRI scans from the BraTS 2020 dataset.The Expectation-Maximization(EM)algorithm is employed to estimate parameters for four tissue classes,generating a new pre-segmented channel that enhances the training and performance of the 3DU-Net model.The proposed GGMM+3D U-Net framework achieved a Dice coefficient of 0.88 for whole tumor segmentation,outperforming both the standard multiscale 3D U-Net(0.84)and MMU-Net(0.85).It also delivered higher Intersection over Union(IoU)scores compared to models trained without preprocessing or with simpler GMM-based segmentation.These results,supported by qualitative visualizations,suggest that GGMM-based preprocessing should be integrated into brain tumor segmentation pipelines to optimize performance.展开更多
The relentless pursuit of advanced X-ray detection technologies has been significantly bolstered by the emergence of metal halides perovskites(MHPs)and their derivatives,which possess remarkable light yield and X-ray ...The relentless pursuit of advanced X-ray detection technologies has been significantly bolstered by the emergence of metal halides perovskites(MHPs)and their derivatives,which possess remarkable light yield and X-ray sensitivity.This comprehensive review delves into cutting-edge approaches for optimizing MHP scintillators performances by enhancing intrinsic physical properties and employing engineering radioluminescent(RL)light strategies,underscoring their potential for developing materials with superior high-resolution X-ray detection and imaging capabilities.We initially explore into recent research focused on strategies to effectively engineer the intrinsic physical properties of MHP scintillators,including light yield and response times.Additionally,we explore innovative engineering strategies involving stacked structures,waveguide effects,chiral circularly polarized luminescence,increased transparency,and the fabrication of flexile MHP scintillators,all of which effectively manage the RL light to achieve high-resolution and high-contrast X-ray imaging.Finally,we provide a roadmap for advancing next-generation MHP scintillators,highlighting their transformative potential in high-performance X-ray detection systems.展开更多
A near eutectic Al−12.6Si alloy was developed with 0.0wt%,2.0wt%,4.0wt%,and 6.0wt%Al−5Ti−1B master alloy.The micro-structural morphology,hardness,tensile strength,elongation,and fracture behaviour of the alloys were s...A near eutectic Al−12.6Si alloy was developed with 0.0wt%,2.0wt%,4.0wt%,and 6.0wt%Al−5Ti−1B master alloy.The micro-structural morphology,hardness,tensile strength,elongation,and fracture behaviour of the alloys were studied.The unmodified Al−12.6Si al-loy has an irregular needle and plate-like eutectic silicon(ESi)and coarse polygonal primary silicon(PSi)particles in the matrix-likeα-Al phase.The P_(Si),E_(Si),andα-Al morphology and volume fraction were changed due to the addition of the Al−5Ti−1B master alloy.The hardness,UTS,and elongation improved due to the microstructural modification.Nano-sized in-situ Al3Ti particles and ex-situ TiB_(2)particles caused the mi-crostructural modification.The fracture images of the developed alloys exhibit a ductile and brittle mode of fracture at the same time.The Al−5Ti−1B modified alloys have a more ductile mode of fracture and more dimples compared to the unmodified alloy.展开更多
A kind of automatic shift schedule optimization method is provided for a tracked vehicle with hydrodynamic-mechanical transmission in order to improve its dynamic performance. A dynamic model of integrated hydrodynami...A kind of automatic shift schedule optimization method is provided for a tracked vehicle with hydrodynamic-mechanical transmission in order to improve its dynamic performance. A dynamic model of integrated hydrodynamic-mechanical transmission is built in MATLAB/Simdriveline environment, and an optimum shift schedule is derived by using iSight software to call the dynamic model above, then the shift schedule is achieved after optimization. The simulation results show that the method is significant to improve the dynamic performance and gear-shifting smoothness theoretically and practically.展开更多
A significant negative aspect in the operation of bridge-type cranes are the technical problems associated with wear of the wheels and the crane track,which causes crane skewing.The main causes of crane skewing includ...A significant negative aspect in the operation of bridge-type cranes are the technical problems associated with wear of the wheels and the crane track,which causes crane skewing.The main causes of crane skewing include unevenness of the crane track,unequal loading of the traction drives depending on the position of the crane trolley,slips and different sizes of travel wheels and combinations of these causes.Firstly,this paper presents a design solution that can be used to detect the magnitude of mechanical stress and deformation of the steel structure of the crane,caused by the effects of skewing.The mechanical stress generated by the transverse forces of the deformed geometric shape of the crane bridge structure is recorded by mechanical stress detectors installed in the inner corners of the crane bridge.The resulting electrical signal from element mechanical voltage detectors,loaded by axial forces,can be used for feedback control of separate crane travel drives controlled by frequency converters.Secondly,this paper presents the calculation of the lateral transverse forces according to CSN 270103 and the determination of the values of mechanical stresses of the deformed steel structure of the crane bridge of a two-girder bridge crane using the finite element method in the program MSC.MARC 2019.Finally,this paper presents the structural and strength design of mechanical stress detectors and the conclusions of laboratory tests of axial force loading of mechanical stress detectors on the test equipment.At the same time,it presents records of the measured axial forces acting in the mechanical stress detectors,arising from the deformation and warping of the crane bridge by the known magnitude of the axial force acting on the crossbeam and from the deformation of the crane bridge caused by the crane operating modes.展开更多
Leukemia is one of the ten types of cancer that causes the biggest death in the world.Compared to other types of cancer,leukemia has a low life expectancy,so an early diagnosis of the cancer is necessary.A new strateg...Leukemia is one of the ten types of cancer that causes the biggest death in the world.Compared to other types of cancer,leukemia has a low life expectancy,so an early diagnosis of the cancer is necessary.A new strategy has been developed to identify various leukemia biomarkers by making blood cancer biosensors,especially by developing nanomaterial applications so that they can improve the performance of the biosensor.Although many biosensors have been developed,the detection of leukemia by using nanomaterials with electrochemical and optical methods is still less carried out compare to other types of cancer biosensors.Even the acoustic and calorimetric testing methods for the detection of leukemia by utilizing nanomaterials have not yet been carried out.Most of the reviewed works reported the use of gold nanoparticles and electrochemical characterization methods for leukemia detection with the object of study being conventional cancer cells.In order to be used clinically by the community,future research must be carried out with a lot of patient blood objects,develop non-invasive leukemia detection,and be able to detect all types of blood cancer specifically with one biosensor.This can lead to a fast and accurate diagnosis thus allowing for early treatment and easy periodic condition monitoring for various types of leukemia based on its biomarker and future design controlable via internet of things(IoT)so that why would be monitoring real times.展开更多
Cellular materials are gaining significant attention in product development due to their unique characteristics,offering superior mechanical performance and functionalities while minimizing material usage and environm...Cellular materials are gaining significant attention in product development due to their unique characteristics,offering superior mechanical performance and functionalities while minimizing material usage and environmental impact.This review article provides an overview of additive manufacturing(AM)technolo-gies for producing aluminum-based cellular materials,focusing on laser AM techniques including laser powder bed fusion and directed energy deposition.The article explores the classification of cellular mate-rials into stochastic foams and nonstochastic lattice structures and discusses conventional manufacturing methods and their limitations.It then examines the emergence of AM as a solution to these limitations,offering advantages such as design customization and optimization,shorter lead times,and the ability to manufacture complex architectures.The article highlights the current research status on AM of cellular materials including lattice shapes,design methods,and AM techniques.It further addresses the current status of AM of aluminum alloys,emphasizing the challenges and advances in producing aluminum-based cellular materials using AM.展开更多
To optimize the excavation of rock using underground blasting techniques,a reliable and simplified approach for modeling rock fragmentation is desired.This paper presents a multistep experimentalnumerical methodology ...To optimize the excavation of rock using underground blasting techniques,a reliable and simplified approach for modeling rock fragmentation is desired.This paper presents a multistep experimentalnumerical methodology for simplifying the three-dimensional(3D)to two-dimensional(2D)quasiplane-strain problem and reducing computational costs by more than 100-fold.First,in situ tests were conducted involving single-hole and free-face blasting of a dolomite rock mass in a 1050-m-deep mine.The results were validated by laser scanning.The craters were then compared with four analytical models to calculate the radius of the crushing zone.Next,a full 3D model for single-hole blasting was prepared and validated by simulating the crack length and the radius of the crushing zone.Based on the stable crack propagation zones observed in the 3D model and experiments,a 2D model was prepared.The properties of the high explosive(HE)were slightly reduced to match the shape and number of radial cracks and crushing zone radius between the 3D and 2D models.The final methodology was used to reproduce various cut-hole blasting scenarios and observe the effects of residual cracks in the rock mass on further fragmentation.The presence of preexisting cracks was found to be crucial for fragmentation,particularly when the borehole was situated near a free rock face.Finally,an optimization study was performed to determine the possibility of losing rock continuity at different positions within the well in relation to the free rock face.展开更多
Integrating innovation and environmental responsibility has become important in pursuing sustainable industrial practices in the contemporary world.These twin imperatives have stimulated research into developing metho...Integrating innovation and environmental responsibility has become important in pursuing sustainable industrial practices in the contemporary world.These twin imperatives have stimulated research into developing methods that optimize industrial processes,enhancing efficiency and effectiveness while mitigating undesirable ecological impacts.This objective is exemplified by the emergence of biochar derived from the thermo-chemical transformation of biomass.This review examines biochar production methods and their potential applications across various aspects of the iron and steel industries(ISI).The technical,economic,and sustainable implications of integrating biochar into the ISI were explored.Slow pyrolysis and hydrothermal carbonization are the most efficient methods for higher biochar yield(25-90%).Biochar has several advantages-higher heating value(30-32 MJ/kg),more porosity(58.22%),and significantly larger surface area(113 m2/g)compared to coal and coke.However,the presence of biochar often reduces fluidity in a coal-biochar mixture.The findings highlighted that biochar production and implementation in ISI often come with higher costs,primarily due to the higher expense of substitute fuels compared to traditional fossil fuels.The economic viability and societal desirability of biochar are highly uncertain and vary significantly based on factors such as location,feedstock type,production scale,and biochar pricing,among others.Furthermore,biomass and biochar supply chain is another important factor which determines its large scale implementation.Despite these challenges,there are opportunities to reduce emissions from BF-BOF operations by utilizing biochar technologies.Overall,the present study explored integrating diverse biochar production methods into the ISI aiming to contribute to the ongoing research on sustainable manufacturing practices,underscoring their significance in shaping a more environmentally conscious future.展开更多
Cold Metal Transfer technology has revolutionized the welding of dissimilar metals and thicker materials by producing improved weld bead aesthetics with controlled metal deposition and low heat-input. In this study, t...Cold Metal Transfer technology has revolutionized the welding of dissimilar metals and thicker materials by producing improved weld bead aesthetics with controlled metal deposition and low heat-input. In this study, the process, weld combinations, laser-CMT hybrid welding and applications of CMT welding are critically reviewed. Microstructure and other weld characteristics have been discussed at length for various base metal combinations. Particularly, the welding of aluminium and steel with better results has been possible with CMT Welding. The results reviewed in this article indicate that the CMT-Laser hybrid welding is more preferable to Laser or Laser hybrid welding. CMT welding has found applications in automobile industries, defence sectors and power plants as a method of additive manufacturing.展开更多
S-N curve and fatigue parameters of 48MnV are obtained using small sample tests and staircase or up and down method, which paves the way for predicting fatigue life of crankshaft made of 48MnV. The fatigue life of the...S-N curve and fatigue parameters of 48MnV are obtained using small sample tests and staircase or up and down method, which paves the way for predicting fatigue life of crankshaft made of 48MnV. The fatigue life of the crankshaft of a six-cylinder engine is calculated using different damage models such as S-N method, normal strain approach, Smoth-Watson-Topper （SWT）Bannantine approach, shear strain approach, and Fatemi-Socie method based on dynamic simulation and finite element analysis （FEA） of crankshaft. The results indicate that the traditional calculation is conservative and the residual fatigue life of crankshaft is sufficient to maintain next life cycle if the crankshaft is remanufactured after its end of life.展开更多
One of the basic ways to reduce polluting emissions of ship power plants is application of innovative devices for on-board energy generation by means of secondary energy resources.The combined gas turbine and diesel e...One of the basic ways to reduce polluting emissions of ship power plants is application of innovative devices for on-board energy generation by means of secondary energy resources.The combined gas turbine and diesel engine plant with thermochemical recuperation of the heat of secondary energy resources has been considered.It is suggested to conduct the study with the help of mathematical modeling methods.The model takes into account basic physical correlations,material and thermal balances,phase equilibrium,and heat and mass transfer processes.The paper provides the results of mathematical modeling of the processes in a gas turbine and diesel engine power plant with thermochemical recuperation of the gas turbine exhaust gas heat by converting a hydrocarbon fuel.In such a plant,it is possible to reduce the specific fuel consumption of the diesel engine by 20%.The waste heat potential in a gas turbine can provide efficient hydrocarbon fuel conversion at the ratio of powers of the diesel and gas turbine engines being up to 6.When the diesel engine and gas turbine operate simultaneously with the use of the LNG vapor conversion products,the efficiency coefficient of the plant increases by 4%–5%.展开更多
The design work of motional cable in products is vital due to the difficulty in estimating the potential issues in current researches.In this paper,a physics-based modeling and simulation method for the motional cable...The design work of motional cable in products is vital due to the difficulty in estimating the potential issues in current researches.In this paper,a physics-based modeling and simulation method for the motional cable harness design is presented.The model,based on continuum mechanics,is established by analyzing the force of microelement in equilibrium.During the analysis procedure,three coordinate systems：inertial,Frenet and main-axis coordinate systems are used.By variable substitution and dimensionless processing,the equation set is discretized by differential quadrature method and subsequently becomes an overdetermined nonlinear equation set with boundary conditions solved by Levenberg-Marquardt method.With the profile of motional cable harness obtained from the integral of arithmetic solution,a motion simulation system based on＂path＂and＂profile＂as well as the experimental equipments is built.Using the same parameters as input for the simulation and the real cable harness correspondingly,the issue in designing,such as collision,can be easily found by the simulation system.This research obtains a better result which has no potential collisions by redesign,and the proposed method can be used as an accurate and efficient way in motional cable harness design work.展开更多
In this paper,the Johnson-Holmquist concrete(JHC)constitutive model is adopted for modeling and simulating the fracture of dolomite.A detailed step-by-step procedure for determining all required parameters,based on a ...In this paper,the Johnson-Holmquist concrete(JHC)constitutive model is adopted for modeling and simulating the fracture of dolomite.A detailed step-by-step procedure for determining all required parameters,based on a series of experiments under quasi-static and dynamic regimes,is proposed.Strain rate coefficients,failure surfaces,equations of state and damage/failure constants are acquired based on the experimental data and finite element analyses.The JHC model with the obtained parameters for dolomite is subsequently validated using quasi-static uniaxial and triaxial compression tests as well as dynamic split Hopkinson pressure bar(SHPB)tests.The influence of mesh size is also analyzed.It shows that the simulated fracture behavior and waveform data are in good agreement with the experimental data for all tests under both quasi-static and dynamic loading conditions.Future studies will implement the validated JHC model in small-and large-scale blasting simulations.展开更多
Parallel manipulators with less than six degrees of freedom （DOF） have been increasingly used in high-speed hybrid machine tools. The structural features of parallel manipulators are dynamic, a characteristic that i...Parallel manipulators with less than six degrees of freedom （DOF） have been increasingly used in high-speed hybrid machine tools. The structural features of parallel manipulators are dynamic, a characteristic that is particularly significant when these manipulators are used in high-speed machine tools. However, normal kinematic control method cannot satisfy the requirements of the control system. Many researchers use model-based dynamic control methods, such as the dynamic feedforward control method. However, these methods are rarely used in hybrid machine tools because of the complex dynamic model of the parallel manipulator. In order to study the dynamic control method of parallel manipulators, the dynamic feedforward control method is used in the dynamic control system of a 3-PSP （prismatic-spherical-prismatic） 3-DOF spatial parallel manipulator used as a spindle head in a high-speed hybrid machine tool. Using kinematic analysis as basis and the Newton-Euler method, we derive the dynamic model of the parallel manipulator. Furthermore, a model-based dynamic feedforward control system consisting of both kinematic control and dynamic control subsystems is established. The dynamic control subsystem consists of two modules. One is used to eliminate the influence of the dynamic characteristics of high-speed movement, and the other is used to eliminate the dynamic disturbances in the milling process. Finally, the simulation model of the dynamic feedforward control system of the 3-PSP parallel manipulator is constructed in Matlab/Simulink. The simulations of the control system eliminating the influence of the dynamic characteristics and dynamic disturbances are conducted. A comparative study between the simulations and the normal kinematic control method is also presented.The simulations prove that the dynamic feedforward control method effectively eliminates the influence of the dynamic disturbances and dynamic characteristics of the parallel manipulator on high-speed machine tools, and significantly improves the trajectory accuracy. This is the first attempt to introduce the dynamic feedfordward control method into the 3-PSP spatial parallel manipulator whose dynamic model is complex and provides a study basis for the real-time dynamic control of the high-speed hybrid machine tools.展开更多
Combining theoretical and experimental modal analyses on self-excited vibration induced by dry friction between two elastic structures, we can explain the high-order sell-excited vibration phenomenon in which water dr...Combining theoretical and experimental modal analyses on self-excited vibration induced by dry friction between two elastic structures, we can explain the high-order sell-excited vibration phenomenon in which water droplets spurt from fourteen or twelve areas of the Chinese culture relic dragon washbasin when it is rubbed with hands, and clarify the mechanism of the singular high-order self-excited vibration. The experimental modes and the practical measured results are presented for a special dragon washbasin. The theoretical results agree well with the experimental ones.展开更多
基金CSIR research grant HCP-26 supported the work reported in this article.
文摘This research paper introduces a soft VR glove that enhances how users interact with virtual objects. It seamlessly integrates discrete modules for sensing and providing haptic feedback, encompassing tactile and kinaesthetic aspects while prioritizing wearability and natural finger movements. The glove employs custom-designed flexible bend sensors with carbon-impregnated film for in-situ joint angle tracking, simplifying the sensing system and enhancing portability. A multi-modal haptic feedback approach includes an innovative pneumatically actuated tactile feedback technique and a motor-tendon-driven kinaesthetic feedback system, providing exceptional realism in virtual object manipulation. The glove’s kinaesthetic feedback lets users perceive virtual objects’ size, shape, and stiffness characteristics. Psychophysical investigations demonstrate how readily the users acclimate to this hardware and prove each module’s effectiveness and synergistic operation. This soft VR glove represents a minimalist, lightweight, and comprehensive solution for authentic haptic interaction in virtual environments, opening new possibilities for applications in various fields.
基金supported by the Hebei province Natural Science Foundation(No.B2023108012)the Science Research Project of Hebei Education Department(No.BJK2024137)+2 种基金the S&T Program of Xingtai(No.2023ZZ096)the National Natural Science Foundation of China(No.62004143)the Key R&D Program of Hubei Province(No.2022BAA084)。
文摘A meticulous design of the local environment at the interface between active species and the support,aimed at optimizing the adsorption of H_(2)O molecules and BH_(4)^(-)anion,offers an ideal strategy for enhancing hydrogen generation via Na BH4hydrolysis through dual activation pathways.Theoretical predictions based on d-band center analysis and electron transfer calculations suggest that introducing-OH functional groups induce charge redistribution,enhancing charge concentration on alk-Ti_(3)C_(2)and facilitating the adsorption and activation of dual active species,H2O molecules and BH4-anion.Inspired by these predictions,the optimized alk-Ti_(3)C_(2)/Ru Oxcatalyst demonstrates the highest catalytic activity,achieving a hydrogen generation rate(HGR)of 9468 m L min^(-1)gcat.^(-1).Both experimental data and theoretical analyses confirm that the-OH functional groups promote charge enrichment on alk-Ti_(3)C_(2),optimizing the adsorption of H_(2)O molecules and BH_(4)^(-)anion,and reducing the dissociation energy barrier of the*OH–H-TS intermediate.This dual activation pathways mechanism lowers the activation energy for Na BH4hydrolysis,significantly enhancing the HGR performance.These findings,guided by theoretical insights,establish alk-Ti_(3)C_(2)/Ru Oxas an efficient catalyst for Na BH4hydrolysis and provide a strong foundation for future hydrogen generation catalyst designs.
基金Princess Nourah Bint Abdulrahman University Researchers Supporting Project number(PNURSP2025R826),Princess Nourah Bint Abdulrahman University,Riyadh,Saudi ArabiaNorthern Border University,Saudi Arabia,for supporting this work through project number(NBU-CRP-2025-2933).
文摘Brain tumor segmentation from Magnetic Resonance Imaging(MRI)supports neurologists and radiologists in analyzing tumors and developing personalized treatment plans,making it a crucial yet challenging task.Supervised models such as 3D U-Net perform well in this domain,but their accuracy significantly improves with appropriate preprocessing.This paper demonstrates the effectiveness of preprocessing in brain tumor segmentation by applying a pre-segmentation step based on the Generalized Gaussian Mixture Model(GGMM)to T1 contrastenhanced MRI scans from the BraTS 2020 dataset.The Expectation-Maximization(EM)algorithm is employed to estimate parameters for four tissue classes,generating a new pre-segmented channel that enhances the training and performance of the 3DU-Net model.The proposed GGMM+3D U-Net framework achieved a Dice coefficient of 0.88 for whole tumor segmentation,outperforming both the standard multiscale 3D U-Net(0.84)and MMU-Net(0.85).It also delivered higher Intersection over Union(IoU)scores compared to models trained without preprocessing or with simpler GMM-based segmentation.These results,supported by qualitative visualizations,suggest that GGMM-based preprocessing should be integrated into brain tumor segmentation pipelines to optimize performance.
基金supported by the National Nature Science Foundation of China(NSFC)(U2241236,1220041913,52473253)the National Key Research and Development Program of China(2022ZDZX0007)+1 种基金Fundamental Research Open Subject Grant Program of Yantai Advanced Materials and Green Manufacturing Laboratory of Shandong Province(AMGM2024F15)Yunnan Major Scientific and Technological Projects(202402AB080011).
文摘The relentless pursuit of advanced X-ray detection technologies has been significantly bolstered by the emergence of metal halides perovskites(MHPs)and their derivatives,which possess remarkable light yield and X-ray sensitivity.This comprehensive review delves into cutting-edge approaches for optimizing MHP scintillators performances by enhancing intrinsic physical properties and employing engineering radioluminescent(RL)light strategies,underscoring their potential for developing materials with superior high-resolution X-ray detection and imaging capabilities.We initially explore into recent research focused on strategies to effectively engineer the intrinsic physical properties of MHP scintillators,including light yield and response times.Additionally,we explore innovative engineering strategies involving stacked structures,waveguide effects,chiral circularly polarized luminescence,increased transparency,and the fabrication of flexile MHP scintillators,all of which effectively manage the RL light to achieve high-resolution and high-contrast X-ray imaging.Finally,we provide a roadmap for advancing next-generation MHP scintillators,highlighting their transformative potential in high-performance X-ray detection systems.
基金The authors would also like to thank NIT,Durgapur RIG#2 project for financial support and the Director of National In-stitute of Technology Durgapur,India,for his continuous en-couragement.
文摘A near eutectic Al−12.6Si alloy was developed with 0.0wt%,2.0wt%,4.0wt%,and 6.0wt%Al−5Ti−1B master alloy.The micro-structural morphology,hardness,tensile strength,elongation,and fracture behaviour of the alloys were studied.The unmodified Al−12.6Si al-loy has an irregular needle and plate-like eutectic silicon(ESi)and coarse polygonal primary silicon(PSi)particles in the matrix-likeα-Al phase.The P_(Si),E_(Si),andα-Al morphology and volume fraction were changed due to the addition of the Al−5Ti−1B master alloy.The hardness,UTS,and elongation improved due to the microstructural modification.Nano-sized in-situ Al3Ti particles and ex-situ TiB_(2)particles caused the mi-crostructural modification.The fracture images of the developed alloys exhibit a ductile and brittle mode of fracture at the same time.The Al−5Ti−1B modified alloys have a more ductile mode of fracture and more dimples compared to the unmodified alloy.
基金Sponsored by the National Natural Science Foudation of China(50905016)
文摘A kind of automatic shift schedule optimization method is provided for a tracked vehicle with hydrodynamic-mechanical transmission in order to improve its dynamic performance. A dynamic model of integrated hydrodynamic-mechanical transmission is built in MATLAB/Simdriveline environment, and an optimum shift schedule is derived by using iSight software to call the dynamic model above, then the shift schedule is achieved after optimization. The simulation results show that the method is significant to improve the dynamic performance and gear-shifting smoothness theoretically and practically.
文摘A significant negative aspect in the operation of bridge-type cranes are the technical problems associated with wear of the wheels and the crane track,which causes crane skewing.The main causes of crane skewing include unevenness of the crane track,unequal loading of the traction drives depending on the position of the crane trolley,slips and different sizes of travel wheels and combinations of these causes.Firstly,this paper presents a design solution that can be used to detect the magnitude of mechanical stress and deformation of the steel structure of the crane,caused by the effects of skewing.The mechanical stress generated by the transverse forces of the deformed geometric shape of the crane bridge structure is recorded by mechanical stress detectors installed in the inner corners of the crane bridge.The resulting electrical signal from element mechanical voltage detectors,loaded by axial forces,can be used for feedback control of separate crane travel drives controlled by frequency converters.Secondly,this paper presents the calculation of the lateral transverse forces according to CSN 270103 and the determination of the values of mechanical stresses of the deformed steel structure of the crane bridge of a two-girder bridge crane using the finite element method in the program MSC.MARC 2019.Finally,this paper presents the structural and strength design of mechanical stress detectors and the conclusions of laboratory tests of axial force loading of mechanical stress detectors on the test equipment.At the same time,it presents records of the measured axial forces acting in the mechanical stress detectors,arising from the deformation and warping of the crane bridge by the known magnitude of the axial force acting on the crossbeam and from the deformation of the crane bridge caused by the crane operating modes.
基金support from the Institut Teknologi Sepuluh Nopember under the project scheme of BRIN awards number:6/IV/KS/05/2023.
文摘Leukemia is one of the ten types of cancer that causes the biggest death in the world.Compared to other types of cancer,leukemia has a low life expectancy,so an early diagnosis of the cancer is necessary.A new strategy has been developed to identify various leukemia biomarkers by making blood cancer biosensors,especially by developing nanomaterial applications so that they can improve the performance of the biosensor.Although many biosensors have been developed,the detection of leukemia by using nanomaterials with electrochemical and optical methods is still less carried out compare to other types of cancer biosensors.Even the acoustic and calorimetric testing methods for the detection of leukemia by utilizing nanomaterials have not yet been carried out.Most of the reviewed works reported the use of gold nanoparticles and electrochemical characterization methods for leukemia detection with the object of study being conventional cancer cells.In order to be used clinically by the community,future research must be carried out with a lot of patient blood objects,develop non-invasive leukemia detection,and be able to detect all types of blood cancer specifically with one biosensor.This can lead to a fast and accurate diagnosis thus allowing for early treatment and easy periodic condition monitoring for various types of leukemia based on its biomarker and future design controlable via internet of things(IoT)so that why would be monitoring real times.
基金the financial support for this research by the Australian Research Council(ARC)through the Discovery Project DP210101862.
文摘Cellular materials are gaining significant attention in product development due to their unique characteristics,offering superior mechanical performance and functionalities while minimizing material usage and environmental impact.This review article provides an overview of additive manufacturing(AM)technolo-gies for producing aluminum-based cellular materials,focusing on laser AM techniques including laser powder bed fusion and directed energy deposition.The article explores the classification of cellular mate-rials into stochastic foams and nonstochastic lattice structures and discusses conventional manufacturing methods and their limitations.It then examines the emergence of AM as a solution to these limitations,offering advantages such as design customization and optimization,shorter lead times,and the ability to manufacture complex architectures.The article highlights the current research status on AM of cellular materials including lattice shapes,design methods,and AM techniques.It further addresses the current status of AM of aluminum alloys,emphasizing the challenges and advances in producing aluminum-based cellular materials using AM.
文摘To optimize the excavation of rock using underground blasting techniques,a reliable and simplified approach for modeling rock fragmentation is desired.This paper presents a multistep experimentalnumerical methodology for simplifying the three-dimensional(3D)to two-dimensional(2D)quasiplane-strain problem and reducing computational costs by more than 100-fold.First,in situ tests were conducted involving single-hole and free-face blasting of a dolomite rock mass in a 1050-m-deep mine.The results were validated by laser scanning.The craters were then compared with four analytical models to calculate the radius of the crushing zone.Next,a full 3D model for single-hole blasting was prepared and validated by simulating the crack length and the radius of the crushing zone.Based on the stable crack propagation zones observed in the 3D model and experiments,a 2D model was prepared.The properties of the high explosive(HE)were slightly reduced to match the shape and number of radial cracks and crushing zone radius between the 3D and 2D models.The final methodology was used to reproduce various cut-hole blasting scenarios and observe the effects of residual cracks in the rock mass on further fragmentation.The presence of preexisting cracks was found to be crucial for fragmentation,particularly when the borehole was situated near a free rock face.Finally,an optimization study was performed to determine the possibility of losing rock continuity at different positions within the well in relation to the free rock face.
基金supported by the Council of Scientific and Industrial Research and The World Academy of Sciences[No.CSIR-HRDG:P-81-1-09].
文摘Integrating innovation and environmental responsibility has become important in pursuing sustainable industrial practices in the contemporary world.These twin imperatives have stimulated research into developing methods that optimize industrial processes,enhancing efficiency and effectiveness while mitigating undesirable ecological impacts.This objective is exemplified by the emergence of biochar derived from the thermo-chemical transformation of biomass.This review examines biochar production methods and their potential applications across various aspects of the iron and steel industries(ISI).The technical,economic,and sustainable implications of integrating biochar into the ISI were explored.Slow pyrolysis and hydrothermal carbonization are the most efficient methods for higher biochar yield(25-90%).Biochar has several advantages-higher heating value(30-32 MJ/kg),more porosity(58.22%),and significantly larger surface area(113 m2/g)compared to coal and coke.However,the presence of biochar often reduces fluidity in a coal-biochar mixture.The findings highlighted that biochar production and implementation in ISI often come with higher costs,primarily due to the higher expense of substitute fuels compared to traditional fossil fuels.The economic viability and societal desirability of biochar are highly uncertain and vary significantly based on factors such as location,feedstock type,production scale,and biochar pricing,among others.Furthermore,biomass and biochar supply chain is another important factor which determines its large scale implementation.Despite these challenges,there are opportunities to reduce emissions from BF-BOF operations by utilizing biochar technologies.Overall,the present study explored integrating diverse biochar production methods into the ISI aiming to contribute to the ongoing research on sustainable manufacturing practices,underscoring their significance in shaping a more environmentally conscious future.
文摘Cold Metal Transfer technology has revolutionized the welding of dissimilar metals and thicker materials by producing improved weld bead aesthetics with controlled metal deposition and low heat-input. In this study, the process, weld combinations, laser-CMT hybrid welding and applications of CMT welding are critically reviewed. Microstructure and other weld characteristics have been discussed at length for various base metal combinations. Particularly, the welding of aluminium and steel with better results has been possible with CMT Welding. The results reviewed in this article indicate that the CMT-Laser hybrid welding is more preferable to Laser or Laser hybrid welding. CMT welding has found applications in automobile industries, defence sectors and power plants as a method of additive manufacturing.
基金This project is supported by National Natural Science Foundation of China(No.50235030).
文摘S-N curve and fatigue parameters of 48MnV are obtained using small sample tests and staircase or up and down method, which paves the way for predicting fatigue life of crankshaft made of 48MnV. The fatigue life of the crankshaft of a six-cylinder engine is calculated using different damage models such as S-N method, normal strain approach, Smoth-Watson-Topper （SWT）Bannantine approach, shear strain approach, and Fatemi-Socie method based on dynamic simulation and finite element analysis （FEA） of crankshaft. The results indicate that the traditional calculation is conservative and the residual fatigue life of crankshaft is sufficient to maintain next life cycle if the crankshaft is remanufactured after its end of life.
文摘One of the basic ways to reduce polluting emissions of ship power plants is application of innovative devices for on-board energy generation by means of secondary energy resources.The combined gas turbine and diesel engine plant with thermochemical recuperation of the heat of secondary energy resources has been considered.It is suggested to conduct the study with the help of mathematical modeling methods.The model takes into account basic physical correlations,material and thermal balances,phase equilibrium,and heat and mass transfer processes.The paper provides the results of mathematical modeling of the processes in a gas turbine and diesel engine power plant with thermochemical recuperation of the gas turbine exhaust gas heat by converting a hydrocarbon fuel.In such a plant,it is possible to reduce the specific fuel consumption of the diesel engine by 20%.The waste heat potential in a gas turbine can provide efficient hydrocarbon fuel conversion at the ratio of powers of the diesel and gas turbine engines being up to 6.When the diesel engine and gas turbine operate simultaneously with the use of the LNG vapor conversion products,the efficiency coefficient of the plant increases by 4%–5%.
基金Supported by National Natural Science Foundation of China(Grant No.51275047)
文摘The design work of motional cable in products is vital due to the difficulty in estimating the potential issues in current researches.In this paper,a physics-based modeling and simulation method for the motional cable harness design is presented.The model,based on continuum mechanics,is established by analyzing the force of microelement in equilibrium.During the analysis procedure,three coordinate systems：inertial,Frenet and main-axis coordinate systems are used.By variable substitution and dimensionless processing,the equation set is discretized by differential quadrature method and subsequently becomes an overdetermined nonlinear equation set with boundary conditions solved by Levenberg-Marquardt method.With the profile of motional cable harness obtained from the integral of arithmetic solution,a motion simulation system based on＂path＂and＂profile＂as well as the experimental equipments is built.Using the same parameters as input for the simulation and the real cable harness correspondingly,the issue in designing,such as collision,can be easily found by the simulation system.This research obtains a better result which has no potential collisions by redesign,and the proposed method can be used as an accurate and efficient way in motional cable harness design work.
文摘In this paper,the Johnson-Holmquist concrete(JHC)constitutive model is adopted for modeling and simulating the fracture of dolomite.A detailed step-by-step procedure for determining all required parameters,based on a series of experiments under quasi-static and dynamic regimes,is proposed.Strain rate coefficients,failure surfaces,equations of state and damage/failure constants are acquired based on the experimental data and finite element analyses.The JHC model with the obtained parameters for dolomite is subsequently validated using quasi-static uniaxial and triaxial compression tests as well as dynamic split Hopkinson pressure bar(SHPB)tests.The influence of mesh size is also analyzed.It shows that the simulated fracture behavior and waveform data are in good agreement with the experimental data for all tests under both quasi-static and dynamic loading conditions.Future studies will implement the validated JHC model in small-and large-scale blasting simulations.
基金supported by National Hi-tech Research and Development Program of China(863 Program, Grant No. 2007AA041901)National S&T Major Project of China(Grant No. 2009ZX04014-035)National Basic Research Program of China (973 Program, Grant No. 2006CB705400)
文摘Parallel manipulators with less than six degrees of freedom （DOF） have been increasingly used in high-speed hybrid machine tools. The structural features of parallel manipulators are dynamic, a characteristic that is particularly significant when these manipulators are used in high-speed machine tools. However, normal kinematic control method cannot satisfy the requirements of the control system. Many researchers use model-based dynamic control methods, such as the dynamic feedforward control method. However, these methods are rarely used in hybrid machine tools because of the complex dynamic model of the parallel manipulator. In order to study the dynamic control method of parallel manipulators, the dynamic feedforward control method is used in the dynamic control system of a 3-PSP （prismatic-spherical-prismatic） 3-DOF spatial parallel manipulator used as a spindle head in a high-speed hybrid machine tool. Using kinematic analysis as basis and the Newton-Euler method, we derive the dynamic model of the parallel manipulator. Furthermore, a model-based dynamic feedforward control system consisting of both kinematic control and dynamic control subsystems is established. The dynamic control subsystem consists of two modules. One is used to eliminate the influence of the dynamic characteristics of high-speed movement, and the other is used to eliminate the dynamic disturbances in the milling process. Finally, the simulation model of the dynamic feedforward control system of the 3-PSP parallel manipulator is constructed in Matlab/Simulink. The simulations of the control system eliminating the influence of the dynamic characteristics and dynamic disturbances are conducted. A comparative study between the simulations and the normal kinematic control method is also presented.The simulations prove that the dynamic feedforward control method effectively eliminates the influence of the dynamic disturbances and dynamic characteristics of the parallel manipulator on high-speed machine tools, and significantly improves the trajectory accuracy. This is the first attempt to introduce the dynamic feedfordward control method into the 3-PSP spatial parallel manipulator whose dynamic model is complex and provides a study basis for the real-time dynamic control of the high-speed hybrid machine tools.
基金The project supported by the National Natural Science Foundation of China (19872003)
文摘Combining theoretical and experimental modal analyses on self-excited vibration induced by dry friction between two elastic structures, we can explain the high-order sell-excited vibration phenomenon in which water droplets spurt from fourteen or twelve areas of the Chinese culture relic dragon washbasin when it is rubbed with hands, and clarify the mechanism of the singular high-order self-excited vibration. The experimental modes and the practical measured results are presented for a special dragon washbasin. The theoretical results agree well with the experimental ones.
