scholarly journals Three-dimensional needle-tip localization by electric field potential and camera hybridization for needle electromyography exam robotic simulator

2016 ◽  
pp. 143
Author(s):  
Siyu He ◽  
José Gómez-Tames ◽  
Wenwei Yu
Keyword(s):  
Electric Field ◽  
Three Dimensional ◽  
Field Potential ◽  
Needle Electromyography ◽  
Electric Field Potential ◽  
Robotic Simulator

Mathematical Modelling of Electrophysical Water Treatment

2021 ◽  
Vol 412 ◽  
pp. 149-162
Author(s):  
Tatiana A. Kudryashova ◽  
Sergey V. Polyakov ◽  
Nikita I. Tarasov
Keyword(s):  
Water Treatment ◽  
Electric Field ◽  
Time Integration ◽  
Three Dimensional ◽  
Field Potential ◽  
System Quality ◽  
Electric Field Potential ◽  
3D Geometry ◽  
Qhd Model ◽  
Volume Method

The problem of mathematical modeling the processes of water treatment from charged particles by electric field is considered. The problem is relevant due to the mass use of cleaning technologies in industry, medicine or the national economy. At the present stage, a significant improvement of purification system quality and the introduction of the technologies for the regeneration of their filtration components are required. Mathematical simulation using computer and supercomputer calculations helps to accelerate the development of new devices and cleaning technologies. On the basis of the chosen purification technology, it is important to create a numerical simulation apparatus with a controlled high accuracy of the calculations. For this purpose, we use a quasi-hydrodynamic (QHD) model of a viscous incompressible fluid flow, a system of convection-diffusion equations taking into account the action of the Lorentz force to describe the propagation of harmful impurities in aqueous medium, and an equation for the electric field potential [1, 2]. The numerical algorithm is based on the finite volume method. It is applied in the case of irregular unstructured meshes. This is important for problems of real two-dimensional (2D) and three-dimensional (3D) geometry. Time integration is performed according to an explicit scheme, which simplifies the procedure for parallelizing the algorithm. The proposed approach was tested on the examples of 2D and 3D geometry with various locations of the electrodes and various values of the potentials. The obtained results of the concentration of the ionic impurities show the possibility of this method to purify water from 10 to 40 percent. A design of a water purifier based on electrophysical purification technology can be developed on the base of this study.

scholarly journals Models of field-aligned currents needful to simulate the substorm variations of the electric field and other parameters observed by EISCAT

1996 ◽  
Vol 14 (12) ◽  
pp. 1356-1361 ◽  
Author(s):  
M. A. Volkov ◽  
A. A. Namgaladze
Keyword(s):  
Electric Field ◽  
Input Data ◽  
Continuity Equation ◽  
Field Potential ◽  
Active Phase ◽  
Time Dependent ◽  
Electron Content ◽  
Polar Cap ◽  
Electric Field Potential ◽  
Time Variations

Abstract. We have used the global numerical model of the coupled ionosphere-thermosphere-protonosphere system to simulate the electric-field, ion- and electron-temperature and -concentration variations observed by EISCAT during the substorm event of 25 March 1987. In our previous studies we adopted the model input data for field-aligned currents and precipitating electron fluxes to obtain an agreement between observed and modelled ionospheric variations. Now, we have calculated the field-aligned currents needful to simulate the substrom variations of the electric field and other parameters observed by EISCAT. The calculations of the field-aligned currents have been performed by means of numerical integration of the time-dependent continuity equation for the cold magnetospheric electrons. This equation was added to the system of the modelling equations including the equation for the electric-field potential to be solved jointly. In this case the inputs of the model are the spatial and time variations of the electric-field potential at the polar-cap boundaries and those of the cold magnetospheric electron concentration which have been adopted to obtain the agreement between the observed and modelled ionospheric variations for the substorm event of 25 March 1987. By this means it has been found that during the active phase of the substorm the current wedge is formed. It is connected with the region of the decreased cold magnetospheric electron content travelling westwards with a velocity of about 1 km s–1 at ionospheric levels.

Homogenization of composite electrets

2015 ◽  
Vol 28 (2) ◽  
pp. 261-283 ◽  
Author(s):  
YOUCEF AMIRAT ◽  
VLADIMIR V. SHELUKHIN
Keyword(s):  
Dielectric Permittivity ◽  
Diffusion Equation ◽  
Electric Field ◽  
Field Potential ◽  
Principal Result ◽  
Interfacial Condition ◽  
Composite Body ◽  
Electric Field Potential ◽  
Bulk Charge ◽  
Interfacial Charge

We study the two-scale homogenization of the diffraction interfacial condition for the diffusion equation relevant to a composite medium which has a periodic structure. The results are applied to the electric field potential within a dielectric composite body when there is a difference in dielectric permittivity between the composite components in the presence of interfacial static charges. The principal result is that the interfacial charge distribution is equivalent to an apparent bulk charge which can be calculated starting from the composite geometry. We perform the corrector analysis and establish that the corrector terms strongly depend on the interfacial charge.

scholarly journals DC field microscopy of Rydberg Li atoms

2016 ◽  
Vol 94 (6) ◽  
pp. 548-557 ◽  
Author(s):  
Dehua Wang ◽  
Shaohao Cheng ◽  
Qiang Chen ◽  
Zhaohang Chen
Keyword(s):  
Electric Field ◽  
Semiclassical Approximation ◽  
Field Potential ◽  
Detector Plane ◽  
Point Energy ◽  
Atomic Core ◽  
Density Distributions ◽  
Scattering Effect ◽  
Electric Field Potential ◽  
Probability Density Distributions

The DC field microscopy of Rydberg Li atoms has been studied on the basis of the semiclassical theory for the first time. In particular, we discuss the atomic core scattering effect in the ionization dynamics of the Rydberg Li atom. Unlike the case of the photoionization of a Rydberg H atom in an electric field, where the photoionization microscopy interference patterns are mainly caused by the Coulomb scattering and the electric field potential, for the photoionization of a Rydberg Li atom in an electric field, the influence of the atomic core scattering effect on the photoionization microscopy interference patterns plays an important role. In addition, the structure of the interference pattern, which contains the spatial component of the electronic wave function, evolves smoothly with the electron energy above the saddle point energy. The observed oscillatory patterns in the electron probability density distributions on the detector plane are interpreted within the framework of the semiclassical approximation, which can be considered as a manifestation of interference between various electron trajectories arriving at a given point from the atom to the detector plane. This study provides some reference values for future experimental research on photoionization microscopy of the non-hydrogen Rydberg atoms in the presence of external fields.

scholarly journals Discrepancies between Predicted and Observed Intergalactic Magnetic Field Strengths from the Universe’s Total Energy: Is it Contained within Submatter Spatial Geometry?

2014 ◽  
Vol 30 ◽  
pp. 18-23 ◽  
Author(s):  
Michael A. Persinger
Keyword(s):  
Electric Field ◽  
Total Energy ◽  
Field Potential ◽  
Gravitational Energy ◽  
Magnetic Intensity ◽  
Electric Field Potential ◽  
Spatial Geometry ◽  
Intergalactic Magnetic Field ◽  
The Universe ◽  
A Current

Although the gravitational energy within the distance of the radius of a singularity for a current estimated mass of the universe is equal to ~1069 Joules, congruent solutions for different ages of the universe reflect changes by a factor of π or 8π for identities. The total energy value is equal to the product of primary constants G·μ·ε·ħ·σ·c2 (which results in power, W) when divided by the area of smallest unit of space (area of a circle with a radius of Planck’s Length) and then multiplied by the universe’s current surface area and age. The conspicuous discrepancies of ~2∙103 between the predicted average magnetic intensity within the universe from that total energy and contemporary measurements can be accommodated by the quantitative product of 21.3π4 derived from the classic four-dimensional metric. The equivalent electric field potential divided by the predicted magnetic intensity results in a velocity that has been suggested to reflect the latency for excess correlations to occur across the universe. The most parsimonious explanation for these results is that a large component of the magnetic manifestation of energy in the universe is recondite or occluded within its submatter spatial structure and that the required cohesion or “diffusivity” throughout the volume involves the electric field component. These quantifications may facilitate understanding of Mach’s principle that any part of the universe is influenced by all of its parts.

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