A novel ground electromagnetic system

Geophysics ◽  
1986 ◽  
Vol 51 (2) ◽  
pp. 396-409 ◽  
Author(s):  
Ian M. Johnson ◽  
Zbigniew B. Doborzynski
Keyword(s):  
Magnetic Field ◽  
Field Survey ◽  
Field Amplitude ◽  
Rough Terrain ◽  
Electromagnetic System ◽  
Moving Source ◽  
Magnetic Field Amplitude ◽  
Survey Results

A novel, moving‐source, ground electromagnetic system has been developed. The system, named the “Genie,” has been in routine field use since 1982. The system is based on measurement of the ratio of magnetic field amplitude at two widely separated frequencies. The design is presented and compared with traditional horizontal loop electromagnetic (HLEM) systems. Field survey results show the system is effective in detecting conductors at shallow to intermediate depths in resistive environments. The system is shown to be roughly equivalent in many aspects to conventional HLEM systems with important advantages in areas of moderate to rough terrain.

The Experimental Research on Horizontal Underground Tank Magnetic Flux Leakage Testing

2015 ◽  
Vol 752-753 ◽  
pp. 1236-1239
Author(s):  
Mu Lin Zheng ◽  
Zhang Wei Ling ◽  
Min Wang ◽  
Shuai Kong ◽  
Wei Can Guo
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Experimental Research ◽  
Field Amplitude ◽  
Magnetic Flux Leakage ◽  
Tank Wall ◽  
Magnetic Field Amplitude ◽  
Corrosion Pits ◽  
Flux Leakage ◽  
Underground Tank

Magnetic flux leakage (MFL) testing is widely used to inspect and characterize defects in storage tank floors, pipelines and other structures. In this paper, magnetic flux leakage testing technology is applied to the horizontal product oil underground tank wall inspection. The artificial defects were prefabricated on the tank wall such as corrosion pits, grooving and other artificial defects to simulate the corrosion, cracks and other actual defects in actual working conditions. The experimental research of the mutual influence between magnetic flux leakage and defects’ parameters were carried out, such as the depth and width of cracks, and depth and diameter of corrosion pits. Then the relationship between the defect’s parameter and magnetic field amplitude was obtained. The experimental results showed that, whether corrosion or crack, the depth is a very important factor affecting the leakage magnetic field amplitude. Especially for crack, width, length and the inclination angle between crack and magnetic field had great influence on the detection of the cracks, and too small angle to lead to misjudgment and undetected of crack. Therefore, single direction inspection may lead to undetected in engineering practice.

scholarly journals Towards improved magnetic fluid hyperthermia: major-loops to diminish variations in local heating

2017 ◽  
Vol 19 (22) ◽  
pp. 14527-14532 ◽  
Author(s):  
Cristina Munoz-Menendez ◽  
David Serantes ◽  
Juan M. Ruso ◽  
Daniel Baldomir
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Applied Magnetic Field ◽  
Local Heating ◽  
Anisotropy Constant ◽  
Field Amplitude ◽  
Magnetic Fluid Hyperthermia ◽  
Magnetic Field Amplitude

A low anisotropy constant allows us to decrease local heating dispersion for a given applied magnetic field amplitude.

Energetic particles and the solar cycle: Impact of solar magnetic field amplitude and geometry on SEPs and GCRs diffusion coefficients

2021 ◽  
Author(s):  
Barbara Perri ◽  
Allan Sacha Brun ◽  
Antoine Strugarek ◽  
Victor Réville
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Solar Cycle ◽  
Diffusion Coefficients ◽  
Solar Magnetic Field ◽  
Energetic Particles ◽  
Field Amplitude ◽  
The Sun ◽  
Magnetic Field Amplitude ◽  
The Magnetic Field

<p>SEPs are correlated with the 11-year solar cycle due to their production by flares and interaction with the inner heliosphere, while GCRs are anti-correlated with it due to the modulation of the heliospheric magnetic field. The solar magnetic field along the cycle varies in amplitude but also in geometry, causing diffusion of the particles along and across the field lines; the solar wind distribution also evolves, and its turbulence affects particle trajectories.</p><p>We combine 3D MHD compressible numerical simulations to compute the configuration of the magnetic field and the associated polytropic solar wind up to 1 AU, with analytical prescriptions of the corresponding parallel and perpendicular diffusion coefficients for SEPs and GCRs. First, we analyze separately the impact of the magnetic field amplitude and geometry for a 100 MeV proton. By varying the amplitude, we change the amplitude of the diffusion by the same factor, and the radial gradients by changing the spread of the current sheet. By varying the geometry, we change the latitudinal gradients of diffusion by changing the position of the current sheets. We also vary the energy, and show that the statistical distribution of parallel diffusion is different for SEPs and GCRs. Then, we use realistic solar configurations, showing that diffusion is highly non-axisymmetric due to the configuration of the current sheets, and that the distribution varies a lot with the distance to the Sun, especially at minimum of activity. With this model, we are thus able to study the direct influence of the Sun on Earth spatial environment in terms of energetic particles. </p>

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