1,720,972 research outputs found
On heat-flux dependent thermopiezoelectricity of nonsimple materials
No full textA theory of thermopiezoelectricity for nonsimple materials is developed by incorporating heat flux as an independent constitutive variable. The linearized version of this theory reveals the presence of second-sound effects. A reciprocity relation which involves two processes at different times and a theorem on the uniqueness of solutions are deduced for anisotropic materials. Finally, a variational principle is established
Stability of thermoelastic diffusion problem of type III in spaces of different dimensions
No full textIn this article, we study the stability issues of a thermoelastic diffusion problem of type III in spaces of different dimensions. First we prove that the one-dimensional problem is exponentially stable without adding damping terms. Then we prove the lack of exponential stability in the two-dimensional space. Moreover, a frictional damping for the elastic component leads to the exponential stability in three-dimensional space. As the form of the damping term depends on the nature of the material, we will distinguish the case of isotropic materials and the case of anisotropic materials
Introducing SNAP: a novel pedal-assisted electric ultralight vehicle
No full textInnovation in transportation and mobility is central to sustainable development. There is a widespread awareness that society would benefit if transportation became more sustainable, promoting economic growth while respecting the environment. This paper introduces SNAP, a four-wheel pedal-assisted electric vehicle that represents a new concept in sustainable mobility towards filling the gap between bicycle and automobile. The choice of the architecture for the hybrid powertrain where the driver pedals are assisted with an electric motor is discussed along with the experimental analysis of the power loss associated with the single components of the transmission. In turn, this knowledge allows the overall quadricycle performance to be evaluated in terms of maximum speed, efficiency, and travel range at varying operating conditions that include vehicle load, road slope, and gear change. It is shown that SNAP can be a promising answer to address the problem of sustainable and safe micro mobility of persons and goods in urban settings
Exponential stability in Mindlin's Form II gradient thermoelasticity with microtemperatures of type III: Mindlin's II gradient thermoelastic
No full textIn this paper, we derive a nonlinear strain gradient theory of thermoelastic materials with microtemperatures taking into account micro-inertia effects as well. The elastic behaviour is assumed to be consistent with Mindlin's Form II gradient elasticity theory, while the thermal behaviour is based on the entropy balance of type III postulated by Green and Naghdi for both temperature and microtemperatures. The work is motivated by increasing use of materials having microstructure at both mechanical and thermal levels. The equations of the linear theory are also obtained. Then, we use the semigroup theory to prove the well-posedness of the obtained problem. Because of the coupling between high-order derivatives and microtemperatures, the obtained equations do not have exponential decay. A frictional damping for the elastic component, whose form depends on the micro-inertia, is shown to lead to exponential stability for the type III model
Uniform Decay for Thermoelastic Diffusion Problem of Type III with Delays
No full textIn this article, we consider a thermoelastic diffusion problem of type III in one space dimension with boundary constant delays. First we prove that the one-dimensional problem is well-posed by the semigroup theory. By introducing a suitable energy and an appropriate Lyapunov functional, we show under smallness conditions that the damping delay effect through heat and mass diffusion conduction is strong enough to uniformly stabilize the system. Moreover, our results can be extended to the case where our system is subjected to other damping functions as the time-varying delay or the distributed delay
Stabilization in extensible thermoelastic Timoshenko microbeam based on modified couple stress theory
No full textIn this article we derive the equations that constitute the nonlinear model of extensible thermoelastic Timoshenko microbeam. The constructed mathematical model is based on the modified couple stress theory which implies prediction of size dependent effects in microbeam resonators, by applying the Hamilton principle to full von Karman equations. This takes account of the effects of extensibility where the dissipations are entirely contributed by temperature. Based on semigroups theory, we establish existence and uniqueness of weak and strong solutions to the derived problem. By an approach based on the Gearhart-Herbst-Pruss-Huang theorem, we prove that the associated linear semigroup (without extensibility) is not analytic in general. In the absence of additional mechanical dissipations, the system is often not highly stable. Then by adding a damping frictional function to the first equation of the derived model and using the multiplier method, we show that the solutions decay exponentially under a condition on the physical coefficients
Overturning Stability for the SNAP Cargo Family of Pedal‐Assisted Ultralight Vehicles
No full textInnovation in transportation and mobility is the foundation for sustainable development. This paper provides details of the SNAP family vehicles, four-wheel pedal-assisted electric vehicles that represent a new concept in sustainable mobility that aims to fill the gap between bicycle and automobile. Special focus is given to the study of the overturning problem for this class of microcars that contribute to two Sustainable Development Goals: Affordable Clean Energy and Sustainable Cities and Communities
Analyticity of solutions to thermoviscoelastic diffusion mixtures problem in higher dimension
No full textIn this paper, we consider the linear theory of binary mixtures for thermoviscoelastic diffusion materials derived by Aouadi et al. (J Therm Stress 41:1414–1431, 2018). We establish the necessary and sufficient conditions to get a dissipation inequality for isotropic centrosymmetric materials. With the help of the semigroup theory of linear operators, we prove the well posedness of the higher-dimensional problem. Then, we show that the associated C-semigroup is analytic. Exponential stability and impossibility of localization of the solutions in time are immediate consequences
Correction to: Introducing SNAP: a novel pedal-assisted electric ultralight vehicle (SN Applied Sciences, (2023), 5, 1, (40), 10.1007/s42452-022-05261-z)
No full textIn this article, the last sentence of the Funding section was incomplete and should have read “The financial support of the projects: Agricultural inTeroperabiLity andAnalysis System (ATLAS), H2020 (Grant No. 857125), and multimodalsensing for individual plANT phenOtyping in agriculture robotics (ANTONIO), ICTAGRI-FOOD COFUND (Grant No. 41946) is gratefully acknowledged.” The original article has been corrected
The SNAP: A Novel Four-Wheel Pedal-Assisted Electric Lightweight Vehicle
No full textInnovation in transportation and mobility is central to sustainable development. There is a widespread awareness that society would benefit if transportation became more sustainable, promoting economic growth while respecting the environment. This paper introduces SNAP, a four-wheel pedal-assisted electric vehicle that represents a new concept in sustainable mobility towards filling the gap between bicycle and automobile
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