Comparison of results of measuring the magnetic field of a crack by flux-gate meters with calculated data obtained within a model of constant magnetic charge density

2008 ◽  
Vol 44 (1) ◽  
pp. 54-58 ◽  
Author(s):  
A. Z. Veksler ◽  
B. V. Gusev ◽  
A. M. Shanaurin ◽  
V. E. Shcherbinin
Keyword(s):  
Magnetic Field ◽  
Charge Density ◽  
Magnetic Charge ◽  
Calculated Data ◽  
Comparison Of Results ◽  
Flux Gate ◽  
The Magnetic Field

FINITE ENERGY ONE-HALF MONOPOLE SOLUTIONS

2012 ◽  
Vol 27 (40) ◽  
pp. 1250233 ◽  
Author(s):  
ROSY TEH ◽  
BAN-LOONG NG ◽  
KHAI-MING WONG
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Topological Charge ◽  
Magnetic Monopole ◽  
Magnetic Charge ◽  
Finite Energy ◽  
Spatial Infinity ◽  
Yang Mills ◽  
The Magnetic Field

We present finite energy SU(2) Yang–Mills–Higgs particles of one-half topological charge. The magnetic fields of these solutions at spatial infinity correspond to the magnetic field of a positive one-half magnetic monopole at the origin and a semi-infinite Dirac string on one-half of the z-axis carrying a magnetic flux of [Formula: see text] going into the origin. Hence the net magnetic charge is zero. The gauge potentials are singular along one-half of the z-axis, elsewhere they are regular.

Magnetic Sensors for Space Applications

2018 ◽  
pp. 248-283 ◽  
Author(s):  
Neoclis Hadjigergiou ◽  
Marios Sophocleous ◽  
Evangelos Hristoforou ◽  
Paul Peter Sotiriadis
Keyword(s):  
Magnetic Field ◽  
Quantum Interference ◽  
Measurement Techniques ◽  
General Information ◽  
Magnetic Sensors ◽  
Normal Operation ◽  
Space Applications ◽  
Flux Gate ◽  
Magneto Resistance ◽  
The Magnetic Field

This chapter is composed of three parts. The first is an introductory part, providing general information about magnetism and related phenomena. Magnetic materials are also discussed and presented. Afterwards, the magnetic field and various measurement techniques are discussed. In the second part, different magnetic sensors used in a laboratory or space are presented. Magnetic sensors that are discussed include anisotropic magneto-resistance (AMR), giant magneto-resistance (GMR), giant magneto-impedance (GMI), flux-gate and superconducting quantum interference device (SQUID). Although some of them may be outdated and well known, they are widespread and they still pose an excellent choice for certain applications. Magnetic cleanliness is an important factor both in calibration and in normal operation of a system; in the third part, current techniques to isolate a system from the external magnetic field providing cleanliness are discussed.

ESTIMATION OF THE MASS OF CARGO DUMP TRUCK

2021 ◽  
pp. 10-17
Author(s):  
A. Nikishechkin ◽  
L. Dubrovin ◽  
V. Davydenko
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Magnetic Field Strength ◽  
Dump Truck ◽  
Traction Motors ◽  
Flux Gate ◽  
Mining Dump Truck ◽  
Generator Frequency ◽  
The Magnetic Field ◽  
Excitation Winding

The article discusses an on-board weighing system for the load of a mining dump truck, which simplifies measurements and, unlike existing systems, does not require the integration of sensors into the structure and electrical circuits of the truck and represents a compact, autonomous device that can be located at any convenient place in the cab. In order to create such a device, it is proposed to use the magnitude of the magnetic field strength generated by DC traction motors as a signal carrying information about the mass of the transported cargo. To measure the magnetic field strength, a flux gate is used, which converts the magnitude of the magnetic field strength into the magnitude of the current. An original circuit for powering the fluxgate excitation winding using a modulated signal generator based on logic elements is proposed. The used power supply scheme allows to exclude the influence of the fluxgate excitation winding on the generator frequency, as well as to increase the fluxgate sensitivity, which makes it possible to install the sensor in any convenient place in the dump truck cabin, and not in the immediate vicinity of the traction motors.

scholarly journals Interinstrument calibration using magnetic field data from the flux-gate magnetometer (FGM) and electron drift instrument (EDI) onboard Cluster

2014 ◽  
Vol 3 (1) ◽  
pp. 1-11 ◽  
Author(s):  
R. Nakamura ◽  
F. Plaschke ◽  
R. Teubenbacher ◽  
L. Giner ◽  
W. Baumjohann ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Data ◽  
Spin Axis ◽  
Electron Drift ◽  
Magnetic Field Data ◽  
Field Magnitude ◽  
Magnetic Field Magnitude ◽  
Flux Gate ◽  
Axis Offset ◽  
The Magnetic Field

Abstract. We compare the magnetic field data obtained from the flux-gate magnetometer (FGM) and the magnetic field data deduced from the gyration time of electrons measured by the electron drift instrument (EDI) onboard Cluster to determine the spin-axis offset of the FGM measurements. Data are used from orbits with their apogees in the magnetotail, when the magnetic field magnitude was between about 20 and 500 nT. Offset determination with the EDI–FGM comparison method is of particular interest for these orbits, because no data from solar wind are available in such orbits to apply the usual calibration methods using the Alfvén waves. In this paper, we examine the effects of the different measurement conditions, such as direction of the magnetic field relative to the spin plane and field magnitude in determining the FGM spin-axis offset, and also take into account the time-of-flight offset of the EDI measurements. It is shown that the method works best when the magnetic field magnitude is less than about 128 nT and when the magnetic field is aligned near the spin-axis direction. A remaining spin-axis offset of about 0.4 ∼ 0.6 nT was observed for Cluster 1 between July and October 2003. Using multipoint multi-instrument measurements by Cluster we further demonstrate the importance of the accurate determination of the spin-axis offset when estimating the magnetic field gradient.

Prediction of the Magneto-Resistance of La0.65Ca0.35MnO3 and La0.8Sr0.2MnO3 via Temperature and Magnetic Field

2013 ◽  
Vol 772 ◽  
pp. 83-88
Author(s):  
Ning Zhu ◽  
Ya Jie Liu
Keyword(s):  
Magnetic Field ◽  
Calculated Data ◽  
Ferromagnetic Phase ◽  
Metal Insulator ◽  
Nonlinear Fitting ◽  
Relative Errors ◽  
Magneto Resistance ◽  
Perovskite Type ◽  
The Magnetic Field ◽  
Crucial Parameter

The resistance associated with temperature and magnetic field is a crucial parameter in researching the physical properties of the Perovskite-type manganites. To find out a suitable method to predicting the resistance of La0.65Ca0.35MnO3and La0.8Sr0.2MnO3in the process from paramagnetic phase to the ferromagnetic phase via the temperature and the magnetic field was the aim of this paper. By the nonlinear fitting, an appreciated analytic expression showing the temperature-dependence resistance both less or higher than the metal-insulator transition temperature,Tc, at different magnetic field was put forward. All of the nonlinear fitting between the measured and the calculated data were so satisfied that the minimum correlation coefficient is below 0.9997, the average relative errors do not exceed 1.0%.

A Study of Magnetic Charge per Unit Area of Dipole Model for the NDE

2007 ◽  
Vol 353-358 ◽  
pp. 2371-2374 ◽  
Author(s):  
Ji Seong Hwang ◽  
Jong Woo Jun ◽  
Se Ho Choi ◽  
Cheol Woong Kim ◽  
Kazuhiro Ogawa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Inverse Problem ◽  
Field Distribution ◽  
Magnetic Charge ◽  
Unit Area ◽  
Model Simulation ◽  
Dipole Model ◽  
Magnetic Field Distribution ◽  
Problem Analysis ◽  
The Magnetic Field

Nondestructive testing using magnetic field is useful for detection of a crack on ferromagnetic material. The magnetic field distribution has to be obtained for quantitative evaluation of crack direction, size, and shape. Also, a crack can be evaluated by using the inverse problem analysis. However, an analysis method using a dipole model can be used to analyze the magnetic field distribution around a crack at a higher speed than the finite element method (FEM). Therefore, a dipole model simulation can provide useful information which can be used for the inverse problem analysis. However, the magnetic charge per unit area, m, and the permeability, μ, has been treated as constants. Therefore, analyzed results have been different from experimental results in most cases. This paper proposes the improved dipole model simulation method, which assumes that the magnetic charges per unit area exist at the section areas, edge lines and summits of a crack. Also, the magnetic charges per unit area were assumed to depend on the square of the crack depth. The improved method is validated by comparing its results with the experiment results obtained with the use of the magnetic camera.

scholarly journals Comments on magnetic black holes

2021 ◽  
Vol 2021 (4) ◽  
Author(s):  
Juan Maldacena
Keyword(s):  
Magnetic Field ◽  
Black Holes ◽  
Radiation Effects ◽  
Magnetic Charge ◽  
Two Dimensional ◽  
Electroweak Symmetry ◽  
Charged Black Holes ◽  
The Standard Model ◽  
Field Lines ◽  
The Magnetic Field

Abstract We discuss aspects of magnetically charged black holes in the Standard Model. For a range of charges, we argue that the electroweak symmetry is restored in the near horizon region. The extent of this phase can be macroscopic. If Q is the integer magnetic charge, the fermions lead to order Q massless two dimensional fermions moving along the magnetic field lines. These greatly enhance Hawking radiation effects.

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