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Electrical Field in Materials
Published in Ahmad Shahid Khan, Saurabh Kumar Mukerji, Electromagnetic Fields, 2020
Ahmad Shahid Khan, Saurabh Kumar Mukerji
In electromagnetics the continuity equation is an empirical law expressing (local) charge conservation. Mathematically, it is a consequence of Maxwell’s equations, although charge conservation is more fundamental than these equations. The continuity equation can be expressed in both integral and differential forms.
Cascade and Coupled-Biquad Switched-Capacitor Filters
Published in John T. Taylor, Qiuting Huang, CRC Handbook of ELECTRICAL FILTERS, 2020
Equations 9 make use of the charge conservation principle, which states that charge is neither created nor destroyed in a closed system. Once the charge transfer has taken place, all currents go to zero, and no further voltage changes occur.
Analysis of the current–voltage curves and saturation currents in burner-stabilised premixed flames with detailed ion chemistry and transport models
Published in Combustion Theory and Modelling, 2018
Memdouh Belhi, Jie Han, Tiernan A. Casey, Jyh-Yuan Chen, Hong G. Im, S. Mani Sarathy, Fabrizio Bisetti
The electric current characterises the rate at which charges flow through the flame surface for a given bias voltage. It was computed by summing up the current density drawn from the flame (J) over the flame surface assumed to be equal to the burner surface area: The electric current density consists of the contributions from the convective, diffusive and drift fluxes summed over all the charged species: As a result of charge conservation, the current density is spatially uniform: This means that the current density is a flame property that depends only on the inflow, mixture properties and bias voltage. The i–V curve of a burner-stabilised flame is then a representation of the complex interaction of ion chemistry and transport in the presence of an electric field [4,27].
Multilayered plate elements with node-dependent kinematics for electro-mechanical problems
Published in International Journal of Smart and Nano Materials, 2018
E. Carrera, S. Valvano, G. M Kulikov
The fundamentals of the modeling of piezoelectric materials have been given in many contributions, in particular in the pioneering works of Mindlin [1], EerNisse [2], Tiersten and Mindlin [3], and in the monograph of Tiersten [4]. The embedding of piezoelectric layers into plates and shells sharpens the requirements of an accurate modeling of the resulting adaptive structure due to the localized electro-mechanical coupling, see e.g. the review of Saravanos and Heyliger [5]. Therefore, within the framework of two-dimensional approaches, layerwise descriptions have often been proposed either for the electric field only (see e.g. the works of Kapuria [6] and Ossadzow-David and Touratier [7]) or for both the mechanical and electrical unknowns (e.g. Heyliger et al. [8]). Ballhause et al. [9] showed that a fourth order assumption for the displacements leads to the correct closed form solution. They conclude that the analysis of local responses requires at least a layer-wise descriptions of the displacements, see also [10]. Benjeddou et al. [11] emphasized that a quadratic electric potential through the plate thickness satisfies the electric charge conservation law exactly. A layerwise mixed finite element is used for piezolaminated plates in [12], and a layerwise mixed least-squares model model is used in [13]. Some of the latest contributions to the Finite Elements (FEs) analysis of piezoelectric plates and shells that are based on exact geometry solid-shell element was developed by Kulikov et al. [14,15], composite laminates consisting of passive and multi-functional materials were analyzed in [16], therefore some important aspects of modeling piezoelectric active thin-walled structures were treated in [17]
A continuum thermomechanical model for the electrosurgery of soft hydrated tissues using a moving electrode
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2020
Wafaa Karaki, Carlos A. Lopez, Diana-Andra Borca Tasciuc, Suvranu De
The thermal contact resistance was estimated to be 10−6 K m2 W−1 and was increased to 1 K m2 W−1 in the 50 W case when the electrical resistance increased due to some loss of contact due to desiccation and vaporization (Karaki et al. 2018) (as is discussed in the results section). Finally, the boundary conditions of the electric charge conservation equations are given with a constant current density applied at the tissue boundary in contact with the electrode and a zero potential at ground.