Although the triboelectric nanogenerator(TENG)has been highlighted as a promising mechanical energy harvester,the requirement of stacking the two individual layers,contact and conductive layers,has been ball and chain...
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Although the triboelectric nanogenerator(TENG)has been highlighted as a promising mechanical energy harvester,the requirement of stacking the two individual layers,contact and conductive layers,has been ball and chain around the ankle of unleashing potential and an advantage of TENGs in their application expansion and ***,one-step fabrication of a single-layered bifunctional composite film-based TENG(BFTENG)driven by the sedimentation of a sol-state precursor is proposed for the extremely facile conversion of various ordinary items into energy *** BF-TENG consists of the polydimethylsiloxane(PDMS)matrix and a carbon nanopowder filler,and it includes both the dielectric part(DP)and conductive part(CP)in one single *** electrical percolation threshold of the incorporated concentration of carbon,ICC,for CP to act as a passage through which induced charges move in BF-TENGs is determined to be 1.0 wt%.The degree of carbon sedimentation in developing the proposed composite can be controlled by the curing speed and the probability of a crosslinking *** maximum peak power is approximately 0.093μW when the contact surface area is 78.5 mm2;the contact frequency is 8 Hz,and the connected load resistance is 9 MΩ.Based on these results,the electrical performance of BF-TENGs in response to various physical stimuli is characterized considering the mechanical energy sources available in daily ***,converting ordinary surfaces such as desks and human skin into BF-TENGs through a single coating procedure and harvesting energy to power an electric device are demonstrated as a proof-of-concept.
A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDO...
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A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.
A robust Adaptive Discrete-time Sliding Mode Controller (ADSMC) is formulated, and is applied to control the pitch motion of a simulated Flapping-Wing Micro Air Vehicle (FWMAV). There is great potential for FWMAVs to ...
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A robust Adaptive Discrete-time Sliding Mode Controller (ADSMC) is formulated, and is applied to control the pitch motion of a simulated Flapping-Wing Micro Air Vehicle (FWMAV). There is great potential for FWMAVs to be used as aerial tools to assist with gathering data and surveying environments. Thanks to modern manufacturing and technology, along with an increased comprehension behind the aerodynamics of wing flaps, these vehicles are now a reality, though not without limitations. Given their diminutive size, FWMAVs are susceptible to real-world disturbances, such as wind gusts, and are sensitive to particular variations in their build quality. While external forces such as wind gusts can be reasonably bounded, the unknown variations in the state may be difficult to characterize or bound without affecting performance. To address these problems, an ADSMC is developed. First, the FWMAV model is converted from continuous-time to discrete-time. Second, an ADSMC for the newly discretized FWMAV model is developed. Using this controller, the trajectory tracking performance of the FWMAV is assessed against a traditional discrete sliding mode controller, and is found to have a decreased chattering frequency and decreased control effort for the same task. Therefore, the ADSMC is assessed as the superior controller, despite being completely unaware of the model parameters or wind gust.
Defective phononic crystals(PnCs)have enabled spatial localization and quantitative amplification of elastic wave *** previous research has focused on applications such as narrow-bandpass filters,ultrasonic sensors,an...
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Defective phononic crystals(PnCs)have enabled spatial localization and quantitative amplification of elastic wave *** previous research has focused on applications such as narrow-bandpass filters,ultrasonic sensors,and piezoelectric energy harvesters,typically operating under the assumption of an external elastic wave ***,a novel approach that uses defective PnCs as ultrasonic actuators to generate amplified waves has ***,the existing studies are limited to the generation of either longitudinal or bending waves,with no research addressing the concurrent generation of ***,this paper proposes a straightforward methodology for the concurrent generation and amplification of both wave types utilizing defect modes at independent defect-band *** piezoelectric elements are attached to the defect,with each element connected to independent external voltage *** precisely adjusting the magnitude and temporal phase differences between the voltage sources,concurrently amplified wave generation is *** paper highlights the advantages of the proposed analytical *** model is both computationally time-efficient and accurate,in comparison with the COMSOL simulation *** instance,in case studies,the analytical model reduces the computational time from one hour to mere seconds,while maintaining acceptable error rates of 1%in peak *** concurrent wave-generation methodology opens new avenues for applications in rotating machinery fault diagnosis,structural health monitoring,and medical imaging.
This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random *** method consists of a generalize...
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This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random *** method consists of a generalized polynomial chaos expansion(GPCE)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data *** the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random *** allows for avoiding repeated computations of invariant substructures while generating the input-output data *** substructuring with static condensation further improves the computational efficiency of the reanalysis without losing ***,the GPCE with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional *** numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPCE using full finite element analyses(FEAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs.
This paper proposes a method to amplify the performance of a flexural-wave-generation system by utilizing the energy-localization characteristics of a phononic crystal(PnC)with a piezoelectric defect and an analytical...
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This paper proposes a method to amplify the performance of a flexural-wave-generation system by utilizing the energy-localization characteristics of a phononic crystal(PnC)with a piezoelectric defect and an analytical approach that accelerates the predictions of such wave-generation *** proposed analytical model is based on the Euler-Bernoulli beam *** proposed analytical approach,inspired by the transfer matrix and S-parameter methods,is used to perform band-structure and time-harmonic analyses.A comparison of the results of the proposed approach with those of the finite element method validates the high predictive capability and time efficiency of the proposed model.A case study is explored;the results demonstrate an almost ten-fold amplification of the velocity amplitudes of flexural waves leaving at a defect-band frequency,compared with a system without the ***,design guidelines for piezoelectric-defect-introduced PnCs are provided by analyzing the changes in wave-generation performance that arise depending on the defect location.
The mechanical and corrosion characteristics of aluminum alloys can be influenced not only by the addition of grain refiners but also by heat treatment that modifies the microstructure and introduces variations in the...
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Many continuous sign language recognition (CSLR) studies adopt transformer-based architectures for sequence modeling due to their powerful capacity for capturing global contexts. Nevertheless, vanilla self-attention, ...
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Nowadays, Industry 4.0 will become urgently implemented in most developed countries, although it is still mainly conceptual. As there are three different aspects making up Industry 4.0 (I4.0), such as digital systems,...
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