Vector Potential or Magnetic Induction?

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Spin Supercurrent in Phenomena of Quantum Non Locality (Quantum Correlations, Magnetic Vector Potential) and in Near Field Antenna Effect

Spin Supercurrent in Phenomena of Quantum Non Locality (Quantum Correlations, Magnetic Vector Potential) and in Near Field Antenna Effect

Field-free magnetic vector potential . In classical electrodynamics, the magnet- ic field of induction B is determined [10] by equation B = curl A , where A is a magnetic vector potential. In shielding of magnetic field, B = 0 , the following may take place: A ≠ 0 . This case is referred to as the field-free vector potential. Magnetic vector potential has a physical meaning of its own. In 1949, Erenberg and Siday predicted the ability of magnetic vector potential to influence directly the characteristics of quantum entities even though there is no electromagnetic field at the location of the entities [11]. In 1959, the possibility of such an effect was considered by Aharonov and Bohm [12]. Subsequently, a great number of experiments have been conducted which confirmed the theoretical predictions [13]. In general, these experiments were as follows (see Figure 2): the beam of electrically charged quantum entities emitted by a source is split into two beams:
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Design and Analysis of Brushless Doubly Fed Induction Machine with 2/6 pole configuration

Design and Analysis of Brushless Doubly Fed Induction Machine with 2/6 pole configuration

Figure 3(a),(b),(c) and (d) respectively show the Magnetic Vector Potential (A) plot in Wb/m, Magnetic Flux Density Contour Plot in Tesla, torque and speed profile of 2/6 pole BDFIM when only the SPW is excited. A clear flux linkage pattern can be observed around 6 poles of the machine and the magnetic flex density is coming within the limits with reference to Table 4 [5]. The torque curve under no load condition consists of ripples in the waveform oscillating around the base zero reference since it is on no load and which is then shifted to full load condition with 25 Nm at 0.56 seconds. For 6 pole mode, the synchronous speed is 1000 rpm as given in equation 2. From the results, it is proved that the machine runs in induction mode of operation with a value of speed below the synchronous speed and when got loaded to 25 Nm, the speed of machine decreased to 780 rpm.
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Faraday's Law of Induction and the Electromagnetic Vector Potential.

Faraday's Law of Induction and the Electromagnetic Vector Potential.

That is to say , since the magnetic field in this hypothetical experiment has absolutely no "physical" contact with the sensing wire, we must conclude that the el[r]

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Magnetic Gearing System

Magnetic Gearing System

With the advent of magnetic gears, researchers have developed a new breed of permanent-magnet machines. These magnetic- geared permanent-magnet machines artfully incorporate the concept of magnetic gearing into the permanent-magnet machines, leading to achieve low-speed high-torque direct-drive operation.Gears and gearboxes are extensively used for speed change and torque transmission in various industrial applications. It is well known that the mechanical gear has a high torque density, but suffers from some inherent problems such as contact friction, noise, heat, vibration and reliability are of great concern. In order to avoid these types of problems we are using magnetic meshing gears. That is the gears are meshed together with the help of magnetic force of attraction without making into contact. By using such kind of gearing systems we can reduce the wear and tear that are commonly seen in mechanical spur gear systems and the magnetic gears works smoothly without any sound and the main advantage of magnetic gearing is it will not get heated as long as it works. Magnetic gearing systems can be used in vehicle transmissions that reduce the friction and improve the efficiency without using any type of additional lubricants. We are using high power rare earth neodymium magnets for the purpose of making gears. Neodymium magnets are powerful magnets which are about 12 times stronger than normal magnets used in speakers.
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Magnetic characterisation of microstructural feature distribution in P9 and T22 steels by major and minor BH loop measurements

Magnetic characterisation of microstructural feature distribution in P9 and T22 steels by major and minor BH loop measurements

Subsequent tempering produced a simulated service entry microstructure, i.e. tempered martensite/bainite as shown in Fig. 1 (b) with the majority of the laths measuring around 380 7 149 nm wide (consistent with previous data [20]) as measured from SEM images. Some areas without clear lath features are present in the SEM images (probably due to non-uniformity in etching) and were not considered in the measurement. Compared to the as-normal- ised P9, there is a signi fi cant decrease in the number density of low angle boundaries as observed from Fig. 2(b) and (d) due to coarsening of the martensitic laths. Many fi ne alloy carbides are present along the lath boundaries, together with some coarse equiaxed precipitates. The size of the latter is inconsistent with their formation during tempering and so they are more likely to be coarse carbides from the service-exposed condition that failed to dissolve completely and remained from the prior solution heat treatment as shown in Fig. 1(b). However, these carbides are so widely separated that they are expected to have a negligible effect on the overall pinning of DW motion, compared to other fi ne precipitates. Although reverse magnetic domains can form around them, there are too few for these precipitates to have a signi fi cant effect on the EM properties.
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Speed Control Of three Phase Induction Motor By Using MRAS

Speed Control Of three Phase Induction Motor By Using MRAS

In recent time there is increase in demand of Induction Motor in industries. In this paper we present the sensorless method for speed estimation and control of three phase induction motor . No sensors are used so this system isrugged and simple. The dynamic model of the induction motor is derived by using a two-phase motor in direct and quadrature axis.

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EE2011 Lecture 5 - Magnetostatics Part II

EE2011 Lecture 5 - Magnetostatics Part II

• When the magnetic flux can be expressed in When the magnetic flux can be expressed in terms of the line integral of vector potential,. terms of the line integral of vector potential,[r]

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Sector sensor array technique for high conductivity materials imaging in magnetic induction tomography

Sector sensor array technique for high conductivity materials imaging in magnetic induction tomography

In the past few years, MIT has been primarily developed for medical imaging applications such as imaging brain function or stroke detection [6]. Previous MIT mainly used fixed coils array, and all coils are located around the periphery of the imaging area. Each coil of the system is both of a sensor coil and a drive coil [7– 10]. The MIT systems achieve circumference measurement by switching the func- tions of coils. The continuous monitoring function of MIT has an advantage in the treatment of traumatic brain injury, however, the brain surgical operations and the wound care unable to supply suitable space for the typical MIT system. It means that the sensors need to give way to the treatment and care in the place of the wound (i.e. the coils cannot take operating area). The system cannot achieve the monitoring of the brain without a complete sensor array in these cases. In the limited-angle MIT imaging study, a part of the coil array (these coils have exciting and detection func- tions) has been directly abandoned. The incomplete measurement images cannot be used as a diagnostic basis. So, the sensor array design needs to achieve complete measurement, and the system can provide enough operating region simultaneously. The distribution of the drive magnetic field is a sector in the imaging area. This fea- ture makes the sensor array can locate high-sensitivity region, and the other area set as the operating region. Therefore, the design strategy of sensor distribution is proposed based on the simulation analysis results of edge magnetic induction. The sensor array locates on the space where the magnetic field has high information effectiveness.
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Electrostatic charging of trigger actuated spray devices

Electrostatic charging of trigger actuated spray devices

Abstract. Electrostatic charging has long been used to improve the efficiency of a range of sprayed liquids. However, the benefits have not until recently been available for exploitation by domestic sprays due to the need for a high voltage power supply. A minimum charge-to-mass ratio (q/m) of 1 × 10 -4 C/kg is generally considered necessary to elicit electrostatic benefits. This level of charge can now be imparted to liquids atomised from trigger-actuated spray devices by a passive system, requiring no power supply. Induction charging was achieved using a triboelectrically charged aluminium electrode. The q/m of the sprayed liquid was dependent upon the charge residing on the induction electrode. The induction electrode was electrically isolated and required a charge of between 0.7 and 1.3 × 10 -8 C to deliver a water spray with a q/m of 1 × 10 -4 C/kg. This level of static charge was readily attained by tribocharging the aluminium with polythene. Once generated, sufficient charge remained on the electrode surface to charge successive sprays without the need for regeneration. The performance advantages for a spray charged in this manner include attraction to and targeting of surfaces and wrap-around onto surfaces not in the direct line of sight.
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Photon and Elementary Particles Theory

Photon and Elementary Particles Theory

For the two photons of vector potential A and − A , their rotation angle frequency ω , and motor direction are same, they can condense into photon- couple, it is shown in Figure 6. With Equation (23), we can find the two photons should be in the balance state, since they suffer the electromagnetic attraction and the spin repulsion. The photon-couple total vector potential, total electric field magnetic field, total spin and momentum all are zero, and the two photons energy should be absolutely transformed into mass of photon-couple, it is

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ANSYS software based simulation of Four-coil Active Magnetic Bearing

ANSYS software based simulation of Four-coil Active Magnetic Bearing

The paper deals with the analysis of 4-coil Active Magnetic Bearing system by the Finite Element Method and the magnetic vector potential formulation. This work proposes an optimal shape and dimensions of the rotor and air gap. This paper also presents how the FEM Analysis can be used to perform the magnetic field analysis in the Active Magnetic Bearing (AMB). This paper reports ANSYS simulation of 4-coil AMB that uses four attraction type magnets are placed in 900 apart from each other. The AMB is an integral part of the industrial rotational machine laboratory model. The nonlinear solution of the magnetic vector potential is determined by using the 2-D finite element method. The force is calculated by Maxwell’s stress tensor method. The electromagnetic field distribution and density analysis allow verifying the designed AMB and the influence of the shaft and coil current changes on the bearing parameters.
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Axisymmetric Magnetic Field Calculation with Zonal Harmonic Expansion

Axisymmetric Magnetic Field Calculation with Zonal Harmonic Expansion

• Comparisons of our elliptic integral formulas with Refs. [19, 21, 27]. The zonal harmonic magnetic field calculation method has several important advantages. First, the field and source equations are separated: during the source constant computations one has to use only the source point and source parameters (geometry, currents, magnetization), but not the field point parameters; and during the field computation the source constants contain already the whole information about the magnetic sources. As an important consequence, the magnetic field calculation with the zonal harmonic method is much faster (in some cases even 1000 times) than with the widely known elliptic integral method. Second, the zonal harmonic method has not only high speed, but also high accuracy, which makes the method especially appropriate for trajectory calculations of charged particles. Due to these properties, no interpolation is necessary when the magnetic field during particle trajectories is computed with the aid of the zonal harmonic method. Third, it is more general and for practical applications more advantageous than the radial series expansion method, which is more widely known in the electron optics literature than the zonal harmonic method. In addition, the zonal harmonic field series formulas are relatively easy to differentiate and integrate, in contrast to the elliptic integral formulas. Furthermore, the low-order source constants can be helpful for system design optimization; for example, vanishing low-order central source constants imply a homogenous magnetic field near the central source point.
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Exact Analytical Method for Air-Gap Main Magnetic Field Computation and Cogging Torque of SMPM Motors

Exact Analytical Method for Air-Gap Main Magnetic Field Computation and Cogging Torque of SMPM Motors

Abstract—This paper presents an exact analytical method to compute the air-gap magnetic field of surface-mounted permanent-magnet (SMPM) motors for evaluating slotting effects accurately. Solution field regions are divided into air-gap domain, permanent magnets (PM) domain, and slot domains. The Laplace’s equations or Poisson’s equations of the sub-domains are contacted by boundary conditions and then solved by exact analytical method. The actual height of slot and distance between slots are taken into account in the computation. Magnetic field distributions and cogging torque computed with the proposed analytical method are compared with those issued from 2-D finite-element method (FEM), and the comparison results are consistent and show the correctness and effectiveness of the proposed analytical method.
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Scalar and Vector Potential-02

Scalar and Vector Potential-02

∂ ∂ − ∂ ∂ = − enables us to reduce the problem of finding the six components associated with the two vectors E E x E y E z = x ˆ + y ˆ + z ˆ and B B x B y B z = x ˆ + y ˆ + z ˆ down to four components – the scalar potential V and the vector potential A A x A y A z = x ˆ + y ˆ + z ˆ . As we saw last semester in P435, B r t ( ) , = ∇× A r t ( ) , and E r t ( ) , = −∇ V r t ( ) , − ∂ A r t ( ) , ∂ t do not enable us to uniquely define / specify / determine the scalar and vector potentials V r t ( ) , and A r t ( ) , ; only potential differences V 2 – V 1 and A 2 − A 1 are physically meaningful…
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CrFe2O4 - BiFeO3 Perovskite Multiferroic Nanocomposites – A Review

CrFe2O4 - BiFeO3 Perovskite Multiferroic Nanocomposites – A Review

The research work reported in this paper mainly deals with the preparation by an economical methods and characterizations of some BiFeO 3 , CeFe 2 O 3 -BiFeO 3 nanocomposites and Carbon Nanotubes. Multiferroics are the potential keystones in upcoming magnetic data storage and spintronics devices provided a simple and fast way can be found to turn their electric and magnetic properties on and off. The present experimental study on synthesis and characterizations of xCrFe 2 O 4 -(1-x) BiFeO 3 Multiferroic nanocomposites, with x = 0.0, 0.1, 0.2, 0.3 and 0.4 can be used as reference work and be extended for further studies with different ‘x’ values for different properties. Further, this work can be extended to study the carbon nanotubes may be reinforced into BiFeO 3 nanoceramics and convert to metallically conductive composites. By using spark- plasma-sintering method [89], we can fabricate nanocrystalline BiFeO 3 matrices that retain the integrity of SWCNT in the matrix. The conductivity of these composites increases with increasing content of CNTs.
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Magnetic induction tomography: a brief review

Magnetic induction tomography: a brief review

Magnetic Induction Tomography (MIT) is a contactless non-invasive imaging technique that interested in mapping the passive electrical properties of a material; conductivity, permittivity and permeability. This paper presents the criteria and previous functional specification involving the development of MIT, focusing in conductivity imaging. Various ways have been implemented from a simple electronic configuration of the front-end sensory circuit, data acquisition system, reconstruction algorithm and graphical user interfacing (GUI) tools. Induction sensors are paramount as it does provide the signal source for time varying magnetic field to the coils. The advantages and limitations of MIT are also presented. Many more advancement can be expected to enhance the lack of MIT especially in spatial resolution and dynamic response of the sensor.
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Analysis of the Influence of Asymmetric Grid on Synchronous Hydro Generator

Analysis of the Influence of Asymmetric Grid on Synchronous Hydro Generator

performance. However, the study about the air gap magnetic field, torque and the change mechanism of the loss in damper bars when the generator is running at asymmetrical state is less. The energy conversion between stator and rotor is realized by the air gap magnetic field. The torque ripple and average torque of generator are respectively related to the stable operation and load capacity. The eddy current loss of the damper bars is the main loss of the generator, which directly determines the efficiency of the generator. Therefore, the study about the air gap flux density, torque and eddy current loss is extremely essential.
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Design of Magnetorheological Fluid Dynamometer which Electric Current and Resisting Moment have Corresponding Relationship

Design of Magnetorheological Fluid Dynamometer which Electric Current and Resisting Moment have Corresponding Relationship

Magnetorheological Fluid, called MFR, is an active branch in the research of intelligent material field. MFR is made of tiny soft magnetic particles and non-conducting magnetic mother liquid with high permeability and low hysteresis of magnetic and mixed with an emulsifier[1]. Under the action of external magnetic field, MRF can instantly ( in milliseconds ) achieve consecutive reversible transition between the low viscosity easy flow of Newtonian fluid and high viscosity hard plastic Bingham[2]. It has a wide range of applications in many fields because of its "liquid", "solid" state transition reversible, controllable and rapid and other outstanding technological features[3]. In the current technology, Bossis and Cutillas et al from French University of Nice has done a lot of work in the MRF mechanism research, especially in the aspect of microstructure analysis[4]. Kormann et al from Germany BASF G have developed a stable of nanoscale MRF[5]. The engineering and technical personnel Lord company has developed a vehicle seat suspension damper[6]. Gm Foister and Gopalswamy developed magnetorheological Fluid and magnetorheological clutch[7]. Jianhua Ni[8] from Xi’an Jiaotong University had carried out a research on the
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2D Analytical Modeling of Magnetic Vector Potential in Surface Mounted and Surface Inset Permanent Magnet Machines

2D Analytical Modeling of Magnetic Vector Potential in Surface Mounted and Surface Inset Permanent Magnet Machines

In this section, the presented analytical model is used to study the magnetic flux density, electromagnetic torque, back- electromotive force, self-inductance and mutual inductance of four prototype motors. The results of analytical method are then verified by the results of finite element method. A 2D model of the studied brushless permanent magnet motor is shown in Fig. 1 and the motor parameters are given in Table 1. The matrix connection between the stator slots and phase connections of each layer for the investigated motors are given by
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Dynamic Wireless Power Transfer in Electric Vehicles using Magnetic Resonance: A Case of Developing Countries

Dynamic Wireless Power Transfer in Electric Vehicles using Magnetic Resonance: A Case of Developing Countries

Abstract—Power pads for charging batteries of electric vehicles in the garage have been in existence for many years but they have not solved the problems facing the users. Electric vehicles stop anywhere on the road as soon as the energy stored in the batteries is exhausted. Stationary charging systems are common and usually located at designated charging stations. To overcome the problems associated with the stationary charging system especially in developing countries, we propose the design of power pad for dynamic battery charging system. This model employs wireless power transfer mechanism, utilizing high quality magnetic resonance. The work leverages on the ability of energy to be transferred efficiently between two magnetically coupled resonating coils in a complex electromagnetic environment. A prototype of the dynamic battery charging system was designed and constructed.
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