scholarly journals Study on the deep conductive geologic structure by magnetovariational method

2015 ◽  
Vol 18 (3) ◽  
pp. 10-18
Author(s):  
Van Thanh Nguyen ◽  
Lieu Nguyen Nhu Vo
Keyword(s):  
Magnetic Field ◽  
Data Interpretation ◽  
Response Functions ◽  
Low Frequencies ◽  
Linear Relations ◽  
Electric And Magnetic Fields ◽  
The Matrix ◽  
Magnetotelluric Method ◽  
Two Parameters ◽  
The Magnetic Field

In the magnetotelluric method, along with the magnetotelluric response functions originating from linear relations between components of the electric and magnetic fields we can determine the magnetovariational response functions derived from linear relations between components of the magnetic field Hx, Hy, Hz. This consideration may significantly enhance the capabilities of the magnetotellurics, since at low frequencies the magnetic field becomes free of nearsurface distortions and shines a nondeceptive light on the deep geoelectric structures. The components of the magnetic field are represented by Wiese–Parkinson matrix 𝑊 . From the matrix, we use the transformations to construct Vozoff tipper 𝑉 , tipper phase ψ, and tipper ellipticity of magnetic field H   to study the electrical heterogeneity. We obtain more information than previous methods because V gives two parameters: direction and amplitude, |V| > |ReW| and |V| > |ImW|; therefore data interpretation has many advantages over previous methods. The results allow us to give meaningful conclusions about the geology, such as mapping some deep conductive geologic structures of the crust.

Transmission line sanitary protective zones. Electromagnetic safety problems

2020 ◽  
pp. 736-736
Author(s):  
N. B. Rubtsova ◽  
A. Y. Tokarskiy
Keyword(s):  
Magnetic Field ◽  
Risk Factor ◽  
Transmission Lines ◽  
General Public ◽  
Field Component ◽  
Regulatory Requirements ◽  
Protection Zones ◽  
Electric And Magnetic Fields ◽  
Health Risk Factor ◽  
The Magnetic Field

The main problems of overhead and cable transmission lines with voltage >=110 kV electric and magnetic fields general public protection are presented. It is shown that it is necessary to develop regulatory requirements for these lines’ sanitary protection zones organization, taking into account the magnetic field component, because its possible health risk factor, up to carcinogenic.

Low-frequency response of a buried object in a lossy ground

1990 ◽  
Vol 68 (1) ◽  
pp. 111-120 ◽  
Author(s):  
A. Helaly ◽  
L. Shafai ◽  
A. Sebak
Keyword(s):  
Magnetic Field ◽  
Integral Equation ◽  
Scattered Field ◽  
Numerical Results ◽  
Low Frequencies ◽  
Impedance Boundary ◽  
Buried Object ◽  
Magnetic Field Integral Equation ◽  
The Magnetic Field ◽  
Field Integral

An approximate method is developed for treating problems of electromagnetic scattering, at low frequencies, from a buried object in a lossy ground and excited by a source located in the air region above. The field incident on the object's surface is calculated using the dyadic Green's functions for a half-space. Neglecting the coupling between the air–Earth interface and the object as a first-order approximation at low frequencies, we formulate the scattering problem in terms of the magnetic-field integral equation in conjunction with the impedance boundary conditions. The method of moments is then used to reduce the magnetic-field integral equation to a matrix one in order to determine the induced surface currents. The total scattered field is separated into two terms. One is the direct scattered field, which acts as if no buried inhomogeneity were present. The other term is the anomalous field, which represents the presence of the inhomogeneity. Solutions have been generated, and the numerical results are examined for a few limiting cases to confirm their accuracy. The formulation is then applied for investigating scattering by buried steel spheres. The numerical results show that the method can be used for detecting buried objects.

scholarly journals Magnetotellurics with a remote magnetic reference

Geophysics ◽  
1979 ◽  
Vol 44 (1) ◽  
pp. 53-68 ◽  
Author(s):  
T. D. Gamble ◽  
W. M. Goubau ◽  
J. Clarke
Keyword(s):  
Magnetic Field ◽  
Standard Deviation ◽  
Magnetic Fields ◽  
Apparent Resistivity ◽  
The Other ◽  
Impedance Tensor ◽  
Free Data ◽  
Electric And Magnetic Fields ◽  
Conventional Methods ◽  
The Magnetic Field

Magnetotelluric measurements were performed simultaneously at two sites 4.8 km apart near Hollister, California. SQUID magnetometers were used to measure fluctuations in two orthogonal horizontal components of the magnetic field. The data obtained at each site were analyzed using the magnetic fields at the other site as a remote reference. In this technique, one multiplies the equations relating the Fourier components of the electric and magnetic fields by a component of magnetic field from the remote reference. By averaging the various crossproducts, estimates of the impedance tensor not biased by noise are obtained, provided there are no correlations between the noises in the remote channels and noises in the local channels. For some data, conventional methods of analysis yielded estimates of apparent resistivities that were biased by noise by as much as two orders of magnitude. Nevertheless, estimates of the apparent resistivity obtained from these same data, using the remote reference technique, were consistent with apparent resistivities calculated from relatively noise‐free data at adjacent periods. The estimated standard deviation for periods shorter than 3 sec was less than 5 percent, and for 87 percent of the data, was less than 2 percent. Where data bands overlapped between periods of 0.33 sec and 1 sec, the average discrepancy between the apparent resistivities was 1.8 percent.

Comparison of the Effects of Bias Voltage and Transverse Magnetic Field on the Macro-Particles Distribution on the Surface of TiN Films Prepared by Arc Ion Plating

2011 ◽  
Vol 337 ◽  
pp. 300-306
Author(s):  
Wen Chang Lang
Keyword(s):  
Magnetic Field ◽  
Transverse Magnetic Field ◽  
Field Intensity ◽  
Magnetic Field Intensity ◽  
Transverse Magnetic ◽  
Key Factor ◽  
Influence Parameter ◽  
Two Parameters ◽  
Influence Degree ◽  
The Magnetic Field

The object of this article is to make research on the influence of transverse magnetic field and pulse bias on macro-particles on the surface of film, find the systematic law and analyze the influence law and reasons of the two parameters (transverse magnetic field and pulse bias), according to the mechanism of arc spot movement and the interaction between macro-particles and plasma. Moreover, this article aims at seeking the most important influence parameter and comparing the effect of the two parameters. Research in this paper indicates that: the key factor is the magnetic field controlled arc spot movement, because the influence of magnetic field on reducing macro-particles is much larger than bias, and the influence degree of bias on macro-particles varies with the magnetic field intensity; action of bias is obvious under the condition of low magnetic field intensity, but as the magnetic field intensity increases, its action becomes weaker and weaker; besides, purification effect of bias on particles in larger size is better than on particles in smaller size.

Effect of electric and magnetic fields on operation of insulin pumps under 400 kV power lines

2020 ◽  
Vol 55 (1) ◽  
pp. 51-54
Author(s):  
L. Korpinen ◽  
R. Pääkkönen ◽  
M. Penttilä
Keyword(s):  
Magnetic Field ◽  
Remote Control ◽  
Insulin Pump ◽  
Test Site ◽  
Control Device ◽  
Power Lines ◽  
Insulin Pumps ◽  
Electric And Magnetic Fields ◽  
Before And After ◽  
The Magnetic Field

The aim was to study the operation of insulin pumps under a 400 kV transmission line (two test places) and possible disturbances that the lines could have caused. Three different insulin pumps were attached one at a time to the subject’s clothes. The diabetes nurse started the pumps before the tests to ensure the correct settings were being utilized. After walking under the power lines when meters were running, she tested if the meters had operated properly. At the first test site (A), the electric field was 5.0–5.1 kV/m and the magnetic field 8.6–10.9 μT, and in the second test place (B), the fields were 7.7–8.5 kV/m and 5.7–9.2 μT. The pumps worked perfectly: no disruption was detected in the flow, display or menu movement, and the events were registered correctly. Only the remote control, which worked well before and after the test, could not reliably receive additional doses. However, the functions of the insulin pump are not dependent on the functionality of the remote control device, so the study suggests that insulin pump users can move safely under the power lines.

Instability of a surface of discontinuity of velocity in a parallel uniform magnetic field

1963 ◽  
Vol 16 (2) ◽  
pp. 187-196 ◽  
Author(s):  
D. D. Mallick
Keyword(s):  
Magnetic Field ◽  
Secular Equation ◽  
Magnetic Reynolds Number ◽  
Wave Number ◽  
Inviscid Fluid ◽  
Dimensionless Wave Number ◽  
Electrically Conducting ◽  
Two Parameters ◽  
Two Sides ◽  
The Magnetic Field

The problem described by the title is investigated when the magnetic field is uniform and parallel to the velocity on the two sides of a surface of discontinuity of velocity in an electrically conducting inviscid fluid. The secular equation depends on two parameters β and N, where β is the ratio of magnetic Reynolds number to dimensionless wave number and N is the ratio of the magnetic to the kinetic energy of the fluid. It is found that the flow is unstable for all values of β and N.

Proton acceleration in three-dimensional non-null magnetic reconnection

2016 ◽  
Vol 82 (5) ◽  
Author(s):  
Z. Akbari ◽  
M. Hosseinpour ◽  
M. A. Mohammadi
Keyword(s):  
Magnetic Field ◽  
Energy Distribution ◽  
Magnetic Reconnection ◽  
Electric Fields ◽  
Three Dimensional ◽  
Null Point ◽  
Proton Acceleration ◽  
Electric And Magnetic Fields ◽  
Field Lines ◽  
The Magnetic Field

In a three-dimensional non-null magnetic reconnection, the process of magnetic reconnection takes place in the absence of a null point where the magnetic field vanishes. By randomly injecting a population of 10 000 protons, the trajectory and energy distribution of accelerated protons are investigated in the presence of magnetic and electric fields of a particular model of non-null magnetic reconnection with the typical parameters for the solar corona. The results show that protons are accelerated along the magnetic field lines away from the non-null point only at azimuthal angles where the magnitude of the electric field is strongest and therefore particles obtain kinetic energies of the order of thousands of MeV and even higher. Moreover, the energy distribution of the population depends strongly on the amplitude of the electric and magnetic fields. Comparison shows that a non-null magnetic reconnection is more efficient in accelerating protons to very high GeV energies than a null-point reconnection.

Suppression of runaway of electrons in a Lorentz plasma. II. crossed electric and magnetic fields

1970 ◽  
Vol 4 (3) ◽  
pp. 441-450 ◽  
Author(s):  
Barbara Abraham-Shrauner
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electric Field ◽  
Electric Fields ◽  
Cyclotron Frequency ◽  
Collision Frequency ◽  
Uniform Electric Field ◽  
Drift Motion ◽  
Electric And Magnetic Fields ◽  
The Magnetic Field

Suppression of runaway of electrons in a weak, uniform electric field in a fully ionized Lorentz plasma by crossed magnetic and electric fields is analysed. A uniform, constant magnetic field parallel to a constant or harmonically time varying electric field does not alter runaway from that in the absence of the magnetic field. For crossed, constant fields the passage to runaway or to free motion as described by constant drift motion and spiral motion about the magnetic field is lengthened in time for strong magnetic fields. The new ‘runaway’ time scale is roughly the ratio of the cyclotron frequency to the collision frequency squared for cyclotron frequencies much greater than the collision frequency. All ‘runaway’ time scales may be given approximately by t2E Teff where tE is the characteristic time of the electric field and Teff is the ffective collision time as estimated from the appropriate component of the electrical conductivity.

scholarly journals Sensitivity of Planaria to Weak, Patterned Electric Current and the Subsequent Correlative Interactions with Fluctuations in the Intensity of the Magnetic Field of Earth

J ◽  
2020 ◽  
Vol 3 (1) ◽  
pp. 79-89
Author(s):  
Victoria Hossack ◽  
Michael Persinger ◽  
Blake Dotta
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Electric Current ◽  
Electromagnetic Fields ◽  
Linear Correlation ◽  
Small Proportion ◽  
Weak Electric Field ◽  
Electric And Magnetic Fields ◽  
The Magnetic Field ◽  
Highly Evolved

Some species of fish show highly evolved mechanisms by which they can detect exogenous electric and magnetic fields. The detection of electromagnetic fields has been hypothesized to exist in humans, despite the lack of specialized sensors. In this experiment, planaria were tested in a t-maze with weak electric current pulsed in one arm to determine if the planaria showed any indication of being able to detect it. It was found that a small proportion of the population seemed to be attracted to this current. Additionally, if the experiment was preceded by a geomagnetic storm, the planaria showed a linear correlation increase in the variability of their movement in response to the presence of the weak electric field. Both of these results indicate that a subpopulation of planaria show some ability to respond to electromagnetic fields.

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