Estimation of the Local Electric field inside an Isotropic Mixture.

1994 ◽  
Vol 347 ◽  
Author(s):  
Georges Roussy ◽  
Jean-Marie Thiebaut ◽  
Med Madi
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Ceramic Material ◽  
Microwave Sintering ◽  
Effective Permittivity ◽  
Heterogeneous Mixture ◽  
Electrical Field ◽  
Two Phase ◽  
Electrical Field Strength ◽  
Phase Mixture

ABSTRACTAs a consequence of the BERGMAN - MILTON theory, which expresses the effective permittivity of a two phase mixture with an integral of a density function, it has been possible to evaluate the local electrical field strength inside a heterogeneous mixture. The developed formula can be used advantageously for modeling the local temperature inside a ceramic material during its microwave sintering.

scholarly journals The Impact of Cross-Linking Effect on the Space Charge Characteristics of Cross-Linked Polyethylene with Different Degrees of Cross-Linking under Strong Direct Current Electric Field

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1149 ◽  
Author(s):  
Shuchao Wang ◽  
Quan Zhou ◽  
Ruijin Liao ◽  
Lai Xing ◽  
Nengcheng Wu ◽  
...  
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Space Charge ◽  
Direct Current ◽  
Cross Linking ◽  
Average Charge ◽  
Electrical Field ◽  
Electrical Field Strength ◽  
The Cross ◽  
The Impact

Cross-linked polyethylene (XLPE) obtained by the crossing-linking reaction of polyethylene (PE) can greatly enhance the mechanical properties and other properties of PE, which makes XLPE widely applied in the field of electric power engineering. However, the space charges can distort the distribution of the electrical field strength in the XLPE applied in the insulation materials, which can shorten the service life of the insulation materials. Therefore, the space charge characteristics of XLPE under the strong direct current (DC) electric field have been the focus of scholars and engineers all over the world. This article has studied the impact of the cross-linking effect on the space charge characteristics of XLPE with different degrees of cross-linking. For this issue, we used dicumyl peroxide (DCP) as the cross-linking agent and low-density polyethylene (LDPE) as the base material for the preparation of samples. Besides, the space charge distribution was measured by the pulsed electro-acoustic method (PEA). In addition, the average charge density as a characteristic parameter was introduced into the experiment, which was used to quantitatively analyze the impact of the cross-linking effect on the space charge characteristics of XLPE with different degrees of cross-linking. Meanwhile, we also explained the impact of the cross-linking effect on XLPE with different degrees of cross-linking from a microscopic point of view. Ultimately, some important conclusions can be obtained. For instance, the cross-linking effect significantly increases the threshold electrical field strength of XLPE, and as the content of cross-linking agent increases, the threshold electrical field strength increases at first and then decreases, and the threshold electrical field strength reaches the maximum value when the content of the cross-linking agent is 1.0% or 2.1%. Besides, the cross-linking effect introduces negative charge traps into the LDPE and increases the densities of the deeper charge traps, and so on. In addition, we have also analyzed the average charge density, and we have summarized the theoretical model of the average charge decay, namely, Q ( t ) = Q 0 + α e − t β , which is very effective for explaining the dissipation characteristics (more conclusive contents can be seen in the conclusion section of this article).

Electrohydrodynamic Printing via Spinneret with Conductive Probe

2013 ◽  
Vol 562-565 ◽  
pp. 1155-1160
Author(s):  
Yi Hong Lin ◽  
Guang Qi He ◽  
Hai Yan Liu ◽  
Jin Wei ◽  
Jian Yi Zheng ◽  
...  
Keyword(s):  
Field Strength ◽  
Applied Voltage ◽  
Industrial Application ◽  
Control Level ◽  
Direct Write ◽  
Electrical Field ◽  
Nano Structure ◽  
Electrical Field Strength ◽  
Electrohydrodynamic Printing ◽  
The Stability

Stability jet ejection and precision deposition are the two keys for industrial application of electrohydrodynamic printing. In this paper, inserted conductive probe is utilized to gain stability jet, which would increase the electrical field strength, reduce the back flow, onset and sustaining voltage. Lower applied voltage would enhance the stability of electrospun jet, in which fine jet can be used to direct-write orderly Micro/Nano-structure. With the guidance and constrain of inserted probe, the oscillating angle range of electrohydrodynamic jet is decreased to 3°from 15°, and the width of printed structures is 21μm in average that is much narrower than that printed from spinneret without probe (74μm in average). Spinneret with tip provides a good way to improve the control level of electrohydrodynamic printing, which would accelerate the industrial application of electrohydrodynamic printed Micro/Nano structure.

Fully Developed Flow of Power-Law Fluid Through a Cylindrical Microfluidic Pipe: Pressure Drop and Electroviscous Effects

2008 ◽  
Author(s):  
Ram P. Bharti ◽  
Dalton J. E. Harvie ◽  
Malcolm R. Davidson
Keyword(s):  
Pressure Drop ◽  
Field Strength ◽  
Charge Density ◽  
Power Law ◽  
Maximum Velocity ◽  
Shear Thickening ◽  
Shear Thinning ◽  
Electrical Field ◽  
Electrical Field Strength ◽  
Fluid Behaviour

Pressure drop and electroviscous effects in the axisymmetric, steady, fully developed, pressure-driven flow of incompressible power-law fluids through a cylindrical microchannel at low Reynolds number (Re = 0.01) have been investigated. The Poisson-Boltzmann equation (describing the electrical potential) and the momentum equations in conjunction with electrical force and power-law fluid rheology have been solved numerically using the finite difference method. The pipe wall is considered to have uniform surface charge density (S = 4) and the liquid is assumed to be a symmetric electrolyte solution. In particular, the influence of the dimensionless inverse Debye length (K = 2, 20) and power-law flow behaviour index (n = 0.2, 1, 1.8) on the EDL potential, ion concentrations and charge density profiles, induced electrical field strength, velocity and viscosity profiles and pressure drop have been studied. As expected, the local EDL potential, local charge density and electrical field strength increases with decreasing K and/or increasing S. The velocity profiles cross-over away from the charged pipe wall with increasing K and/or decreasing n. The maximum velocity at the center of the pipe increases with increasing n and/or increasing S and/or decreasing K. The shear-thinning fluid viscosity is strongly dependent on K and S, whereas the shear-thickening viscosity is very weakly dependent on K and S. For fixed K, as the fluid behaviour changes from Newtonian (n = 1) to shear-thinning (n < 1), the induced electrical field strength increases and maximum velocity reduces. On the other hand, the change in fluid behaviour from Newtonian (n = 1) to shear-thickening (n > 1) decreases the electrical field strength and increases the maximum velocity. The non-Newtonian effects on maximum velocity and pressure drop are stronger in shear-thinning fluids at small K and large S, the shear-thickening fluids show opposite influence. Electroviscous effects enhance with decreasing K and/or increasing S. The electroviscous effects show complex dependence on the non-Newtonian tendency of the fluids. The shear-thickening (n > 1) fluids and/or smaller K show stronger influence on the pressure drop and thus, enhance the electroviscous effects than that in shear-thinning (n < 1) fluids and/or large K where EDL is very thin.

Experimental Study of Melt Electrospinning in Parallel Electrical Field

2011 ◽  
Vol 221 ◽  
pp. 111-116 ◽  
Author(s):  
Ming Feng Hao ◽  
Yong Liu ◽  
Xue Tao He ◽  
Peng Cheng Xie ◽  
Wei Min Yang
Keyword(s):  
Experimental Study ◽  
Field Strength ◽  
Electric Field ◽  
Electric Field Strength ◽  
Melt Spinning ◽  
Fiber Diameter ◽  
The Other ◽  
Electrical Field ◽  
Melt Electrospinning ◽  
Plate Area

In this paper, self-designed electrospinning equipment was used to make a series of electrospinning experiments with materials of polypropylene. The influences of the receiver area, the upper plate area, and the overlapping area between the receiver and the upper plate, on the melt spinning electric field, the spinning efficiency, and the fiber diameter, were investigated respectively. The results showed that when the other parameters were kept unchanged, with the increase of the receiver’s diameter, the electric field strength and spinning efficiency increased, and the fiber diameter increased at first and then decreased; the bigger the overlapping area between the receiver and the upper plate, the more stable the vertical spinning path.

Comparative study on electro-microfiltration (EMF) of water containing different carbon nanotubes (CNTs)

2013 ◽  
Vol 67 (6) ◽  
pp. 1247-1253 ◽  
Author(s):  
Yu-Hsiang Weng ◽  
Hsin-Chieh Wu ◽  
Kung-Cheh Li
Keyword(s):  
Carbon Nanotubes ◽  
Field Strength ◽  
Removal Efficiency ◽  
Pure Water ◽  
Applied Pressure ◽  
Convective Transport ◽  
Single Wall Carbon Nanotubes ◽  
Electrical Field ◽  
Electrical Field Strength ◽  
Electrical Voltage

Disposal and penetration of carbon nanotubes (CNTs) into the environment have raised increasing concerns over the years. In this study, a laboratory scale electro-microfiltration (EMF) was used to treat water containing single wall carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs). The goal was to examine and compare the performance during EMF of SWCNT and MWCNT. The results showed that the initial flux was increased as the applied electrical voltage increased. At an applied pressure of 49 kPa, the final flux was comparable to pure water flux when the applied electrical field strength was greater than the critical electrical field strength (Ecritical). In addition, dissolved organic carbon (DOC) removal efficiency increased as the electrical voltage increased. Due to high convective transport of organic matter toward the membrane at 98 kPa, a decrease in DOC removal efficiency with increasing electrical field strength was observed. Overall, the fluxes and DOC removal efficiencies for EMF of SWCNT and MWCNT were not significantly different with a 95% confidence.

Effect of spin–orbit coupling on the hot-electron energy relaxation in nanowires

2020 ◽  
Vol 34 (32) ◽  
pp. 2050322
Author(s):  
A. L. Vartanian ◽  
A. L. Asatryan ◽  
A. G. Stepanyan ◽  
K. A. Vardanyan ◽  
A. A. Kirakosyan
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Electron Temperature ◽  
Electron Energy ◽  
Power Loss ◽  
Continuum Theory ◽  
Energy Relaxation ◽  
Spin Orbit ◽  
Hot Electron ◽  
Electrical Field Strength

The energy relaxation of hot electrons is proposed based on the spin–orbit (SO) interaction of both Rashba and Dresselhaus types with the effect of hot phonons. A continuum theory of optical phonons in nanowires taking into account the influence of confinement is used to study the hot-electron energy relaxation. The energy relaxation due to both confined (CO) and interface (IO) optical phonon emission on nanowire radius, electrical field strength, parameters of SO couplings and electron temperature is calculated. For considered values of the nanowire radius as well as other system parameters, scattering by IO phonons prevails over scattering by CO phonons. The presence of an electric field leads to the decrease of power loss in transitions between states with the same spin quantum numbers. With the increase of the electric field strength, the influence of the Dresselhaus SO interaction on the energy relaxation rate decreases. The effect of SO interaction does not change the previously obtained increasing dependence of power loss on electron temperature. The sensitivity of energy relaxation to the electric field also through the Rashba parameter allows controlling the rate of energy by electric field.

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