Macro electromechanical milling has recently attracted increasing attention because numerous large thin-walled structures composed of difficult-to-cut materials are employed in the aerospace *** paper reviews recent d...
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Macro electromechanical milling has recently attracted increasing attention because numerous large thin-walled structures composed of difficult-to-cut materials are employed in the aerospace *** paper reviews recent developments in state-of-the-art macro electromechanical *** fundamental aspects of material removal mechanisms,such as the generation and breakdown behaviors of passive oxide films of typical difficult-to-cut materials,were *** methods for breaking down passive films are summarized,and simulation methods for the machining process coupling multiple physical fields are *** electrochemical milling methods,including fly mode electrochemical milling and sink electrochemical milling,are *** made to improve process performance,such as the material removal rate,surface quality,and machining accuracy,are *** addition,the main hybrid electrochemical milling methods,including electrochemical discharge milling,mechano-electrochemical milling,and electrochemical mill grinding,are also presented.
The urgent demand for clean energy solutions has intensified the search for advanced storage materials, with rechargeable alkali-ion batteries(AIBs) playing a pivotal role in electrochemical energy storage. Enhancing ...
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The urgent demand for clean energy solutions has intensified the search for advanced storage materials, with rechargeable alkali-ion batteries(AIBs) playing a pivotal role in electrochemical energy storage. Enhancing electrode performance is critical to addressing the increasing need for high-energy and high-power AIBs. Next-generation anode materials face significant challenges, including limited energy storage capacities and complex reaction mechanisms that complicate structural ***-based materials have emerged as promising candidates for AIBs due to their inherent advantages. Recent research has increasingly focused on the development of heterojunctions as a strategy to enhance the performance of Sn-based anode materials. Despite significant advances in this field, comprehensive reviews summarizing the latest developments are still sparse. This review provides a detailed overview of recent progress in Sn-based heterojunction-type anode materials. It begins with an explanation of the concept of heterojunctions, including their fabrication, characterization, and classification. Cuttingedge research on Sn-based heterojunction-type anodes for AIBs is highlighted. Finally, the review summarizes the latest advancements in heterojunction technology and discusses future directions for research and development in this area.
This paper aims to propose correlations to predict pressure gradient,friction factor and fluid phase hold-up in liquid-liquid horizontal pipe *** develop the correlations,experiments are conducted using high viscous o...
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This paper aims to propose correlations to predict pressure gradient,friction factor and fluid phase hold-up in liquid-liquid horizontal pipe *** develop the correlations,experiments are conducted using high viscous oils(202 and 630 mPa⋅s)in a steel pipe of length 11.25 m and length-to-diameter ratio of *** addition,the experimental data from the literature comprising wide range of flow and fluid properties is *** the analysis,the liquid-liquid pipe flow data is categorized into two as:stratified and *** existing friction factor correlations are modified to incorporate the effects of viscosity of the oil phase,interfacial curvature(contact/wetting angle-in lieu of material of the pipe)and fluid phase *** the two-fluid model of stratified flow,the wall stress and interfacial stress correlations are substituted with superficial velocities of fluids and superficial Reynolds numbers of fluid phases replacing fluid phase velocities and fluid Reynolds ***,for dispersed flow,an effective Reynolds number is described as the sum of superficial Reynolds number of oil and water *** the generally employed mean or mixture Reynolds number with the effective Reynolds number into the existing single-phase turbulent flow friction factor correlation,an effective friction factor for oil-water flow is *** the proposed correlations,the pressure gradient across the oil-water flow and hold-up volume fraction are predicted with significant reduction in error compared with that of conventionally employed *** average error and standard deviation values of−7.06%,20.72%and 0.31%,18.79%are found for stratified flow and dispersed flow respectively.
Fiber laser micromachining is found extensive applications at industrial level because it is cheap and simple to *** to its high strength and low conductivity titanium is difficult to machine with conventional *** thi...
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Fiber laser micromachining is found extensive applications at industrial level because it is cheap and simple to *** to its high strength and low conductivity titanium is difficult to machine with conventional *** this investigation,micro holes were fabricated using a 30 W fiber laser on 2 mm thickα-titanium(Grade 2)and the process parameters were optimized through response surface methodology(RSM)and teaching learning-based optimization(TLBO)*** runs were designed as per rotatable central composite design(RCCD).Material removal rate(MRR),hole circularity(HC),deviation in diameter(DEV)and heat affected zone(HAZ)were selected as output.A third-order polynomial prediction model was established using *** of variance(ANOVA)suggested that the developed model was 93.5%*** impact of input factors on responses were studied by 3D surface *** desirability indicates that optimum micro drilling conditions are scan speed 275.43 mm/s,frequency 24.61 kHz,power 36.23%and number of passes *** indicates that optimum micro drilling conditions are scan speed 100 mm/s,frequency 20 kHz,power 20%and number of passes *** between RSM and TLBO suggested that TLBO provided better optimization *** morphology of the fabricated micro holes were analyzed with scanning electron microscopy(SEM).
The twin-body plasma arc has the decoupling control ability of heat transfer and mass transfer,which is beneficial to shape and property control in wire arc additive *** this paper,with the wire feeding speed as a cha...
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The twin-body plasma arc has the decoupling control ability of heat transfer and mass transfer,which is beneficial to shape and property control in wire arc additive *** this paper,with the wire feeding speed as a characteristic quantity,the wire melting control ability of twin-body plasma arc was studied by adjusting the current separation ratio(under the condition of a constant total current),the wire current/main current and the position of the wire in the arc axial *** results showed that under the premise that the total current remains unchanged(100 A),as the current separation ratio increased,the middle and minimum melting amounts increased approximately synchronously under the effect of anode effect power,the first melting mass range remained constant;the maximum melting amount increased twice as fast as the middle melting amount under the effect of the wire feeding speed,and the second melting mass range was *** the wire current increased,the anode effect power and the plasma arc power were both factors causing the increase in the wire melting amount;however,when the main current increased,the plasma arc power was the only factor causing the increase in the wire melting *** average wire melting increment caused by the anode effect power was approximately 2.7 times that caused by the plasma arc *** minimum melting amount was not affected by the wire-torch distance under any current separation ratio *** the current separation ratio increased and reached a threshold,the middle melting amount remained constant with increasing wire-torch *** the current separation ratio continued to increase and reached the next threshold,the maximum melting amount remained constant with the increasing wire-torch *** effect of the wire-torch distance on the wire melting amount reduced with the increase in the current separation *** this study,the decoupling mechanism and ability of this innovative
During the metal cutting process, especially in continuous contact conditions like turning, the challenge of lubricants failing to effectively reach the cutting point remains unresolved. Micro-textured cutting tools o...
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During the metal cutting process, especially in continuous contact conditions like turning, the challenge of lubricants failing to effectively reach the cutting point remains unresolved. Micro-textured cutting tools offer a potential solution for tool-chip contact challenges. Inspired by the evolutionary achievements of the biosphere, micro-textures are expected to overcome lubrication limitations in cutting zones. Drawing on the anti-gravity water transport seen at the mouth edge of the Nepenthes plant, an innovative microchannel with Nepenthes-shaped contours was designed on the rake face to enable controlled lubricant transport. However, the dynamics of lubricant delivery on textured surfaces are not fully understood. This study first analyzed the microstructure and water transport mechanism of Nepenthes to reconstruct a micro-textured surface for controlled lubricant transport. A dynamic model was then developed to describe lubricant transport within open microchannels, with mathematical simulations predicting transport speed and flow distance. To validate this model, diffusion experiments of alumina soybean oil nanolubricant on polycrystalline diamond(PCD) cutting tool surfaces were conducted, showing an average prediction deviation of 5.01%. Compared with the classical Lucas-Washburn model, the new model improved prediction accuracy by 4.72%. Additionally, comparisons were made to examine droplet spreading and non-uniform diffusion on textured surfaces, revealing that the T2 surface exhibited the strongest unidirectional diffusion characteristics. The contact angle ratio, droplet unidirectional spreading ratio, and droplet spreading aspect ratio were 0.48, 1.75, and 3.99, respectively. Finally, the anti-wear, friction-reducing, and efficiency-enhancing mechanisms of micro-textured surfaces in minimum quantity lubrication turning were analyzed. This approach may support continuous cutting of difficult-tomachine materials.
This paper addresses the verification of strong currentstate opacity with respect to real-time observations generated from a discrete-event system that is modeled with time labeled Petri nets. The standard current-sta...
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This paper addresses the verification of strong currentstate opacity with respect to real-time observations generated from a discrete-event system that is modeled with time labeled Petri nets. The standard current-state opacity cannot completely characterize higher-level security. To ensure the higher-level security requirements of a time-dependent system, we propose a strong version of opacity known as strong current-state opacity. For any path(state-event sequence with time information)π derived from a real-time observation that ends at a secret state, the strong current-state opacity of the real-time observation signifies that there is a non-secret path with the same real-time observation as π. We propose general and non-secret state class graphs, which characterize the general and non-secret states of time-dependent systems, respectively. To capture the observable behavior of non-secret states, a non-secret observer is ***, we develop a structure called a real-time concurrent verifier to verify the strong current-state opacity of time labeled Petri nets. This approach is efficient since the real-time concurrent verifier can be constructed by solving a certain number of linear programming problems.
Moles exhibit highly effective capabilities due to their unique body structures and digging techniques,making them ideal models for biomimetic ***,a major challenge for mole-inspired robots lies in overcoming resistan...
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Moles exhibit highly effective capabilities due to their unique body structures and digging techniques,making them ideal models for biomimetic ***,a major challenge for mole-inspired robots lies in overcoming resistance in granular media when burrowing with *** the absence of effective forepaw design strategies,most robotic designs rely on increased power to enhance *** address this issue,this paper employs Resistive Force Theory to optimize mole-inspired forepaws,aiming to enhance burrowing *** analyzing the relationship between geometric parameters and burrowing forces,we propose several forepaw design *** granular resistance assessments,an effective forepaw configuration is identified and further refined using parameters such as longitudinal and transverse ***,the Particle Swarm Optimization algorithm is applied to determine the optimal forepaw *** force-loading tests,the optimized forepaw demonstrated a 79.44%reduction in granular lift force and a 22.55%increase in propulsive force compared with the control *** robotic burrowing experiments,the optimized forepaw achieved the longest burrow displacement(179.528 mm)and the lowest burrowing lift force(0.9355 mm/s),verifying its effectiveness in reducing the lift force and enhancing the propulsive force.
Preface: 4th International e-Conference on Recent Advancement in mechanicalengineering and technology (ICRAMET 2021), AIP Conference Proceedings, Volume 2523,
Preface: 4th International e-Conference on Recent Advancement in mechanicalengineering and technology (ICRAMET 2021), AIP Conference Proceedings, Volume 2523,
This study focuses on combining spent alumina catalyst (SAC) with carbonized date palm fiber (CDPF) to create a hybrid combination that is integrated into a metal matrix using waste aluminum. The research takes a thor...
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