Magnetic field of a direct current in a cylindrical‐shaped conductor imbedded in a resistive half‐space beneath a conductive surface layer

1989 ◽  
Vol 66 (10) ◽  
pp. 4587-4593 ◽  
Author(s):  
A. A. Inayat‐Hussain
Keyword(s):  
Magnetic Field ◽  
Surface Layer ◽  
Half Space ◽  
Direct Current ◽  
Conductive Surface

A downhole magnetometric resistivity technique for electrical sounding beneath a conductive surface layer

Geophysics ◽  
1988 ◽  
Vol 53 (4) ◽  
pp. 528-536 ◽  
Author(s):  
R. N. Edwards
Keyword(s):  
Magnetic Field ◽  
Surface Layer ◽  
Magnetic Fields ◽  
Current Source ◽  
Diagnostic Ratios ◽  
Sea Floor ◽  
Earth Resistivity ◽  
Conductive Surface ◽  
Electrical Sounding ◽  
The Magnetic Field

The magnetometric resistivity (MMR) method has not been used systematically for vertical electrical sounding because surficial measurements of the magnetic field caused by static current flow from a point source of current at the surface are independent of the form of the variation of earth resistivity with depth. However, data obtained from an adaptation of the MMR method in which the ratio of the magnetic fields below and above a known conductive surface layer is measured as a function of the horizontal range from the current source can be inverted to obtain the unknown resistivity of deeper material. The practical limitation is that the integrated conductivity of the surface layer must not be much smaller than the integrated conductivity of the unknown zone in order to observe diagnostic ratios significantly different from unity. The expressions derived for the magnetic‐field ratio and for the sensitivity of the ratio to changes in the resistivity of a plane‐layered unknown zone are closed‐form inverse Hankel transforms. The transforms are evaluated analytically for a model of constant, uniform resistivity. One possible geotechnical application of the method is the detection of offshore, resistive permafrost beneath the shallow Beaufort Sea. A theoretical design study in which ratios of the magnetic fields at the bottom and top of the sea are synthesized and the sensitivity of those ratios to changes in sea‐floor resistivity is determined as a function of range and depth, respectively, reveals that the resistivity of a permafrost zone 50 m thick buried 20 m below the sea floor can be identified. The maximum range needed is of the order of 200 m, which appears to be smaller than the maximum spacing required for a Schlumberger sounding to yield similar information.

Modified Moore–Gibson–Thompson photo-thermoelastic model for a rotating semiconductor half-space subjected to a magnetic field

2021 ◽  
pp. 2150163
Author(s):  
A. E. Abouelregal ◽  
Hijaz Ahmad ◽  
S. K. Elagan ◽  
Nawal A. Alshehri
Keyword(s):  
Magnetic Field ◽  
Half Space ◽  
Plasma Waves ◽  
Angular Speed ◽  
Semiconducting Materials ◽  
Thermoelastic Model ◽  
Mode Method ◽  
Heat Transport Equation ◽  
Effects Of Rotation ◽  
Improved Model

This paper focuses on studying thermal, elastic and coupled plasma waves, in the sense of a photo-thermal process transport within an infinite semiconductor medium. In order to study photo-thermal interactions in two-dimensional semiconducting materials, a new mathematical model based on the Moore–Gibson–Thompson equation (MGTE) is implemented. The MGTE model involving the Green–Naghdi model of type III as well as the heat transport equation proposed by Lord and Shulman. We consider the semi-conductor half-space is rotated at a uniform angular speed and magnetized. The analysis of the distribution of thermophysical fields has been extracted by a normal mode method, represented graphically and discussed. The results predicted by the new and improved model have been compared with the generalized and classic ones. In addition, all field quantities have been examined for effects of rotation, a lifetime of the photo-generated, and the applied magnetic field.

Grain refinement of pure aluminum by direct current pulsed magnetic field and inoculation

2014 ◽  
Vol 24 (5) ◽  
pp. 1295-1300 ◽  
Author(s):  
Hang CHEN ◽  
Jin-chuan JIE ◽  
Ying FU ◽  
Hong-jun MA ◽  
Ting-ju LI
Keyword(s):  
Magnetic Field ◽  
Grain Refinement ◽  
Direct Current ◽  
Pure Aluminum ◽  
Pulsed Magnetic Field

scholarly journals Rotation and Magnetic Field Effect on Surface Waves Propagation in an Elastic Layer Lying over a Generalized Thermoelastic Diffusive Half-Space with Imperfect Boundary

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
S. M. Abo-Dahab ◽  
Kh. Lotfy ◽  
A. Gohaly
Keyword(s):  
Magnetic Field ◽  
Surface Waves ◽  
Half Space ◽  
Attenuation Coefficient ◽  
Elastic Layer ◽  
Finite Thickness ◽  
Relaxation Times ◽  
Magnetic Field Effect ◽  
Plane Boundary ◽  
Special Cases

The aim of the present investigation is to study the effects of magnetic field, relaxation times, and rotation on the propagation of surface waves with imperfect boundary. The propagation between an isotropic elastic layer of finite thickness and a homogenous isotropic thermodiffusive elastic half-space with rotation in the context of Green-Lindsay (GL) model is studied. The secular equation for surface waves in compact form is derived after developing the mathematical model. The phase velocity and attenuation coefficient are obtained for stiffness, and then deduced for normal stiffness, tangential stiffness and welded contact. The amplitudes of displacements, temperature, and concentration are computed analytically at the free plane boundary. Some special cases are illustrated and compared with previous results obtained by other authors. The effects of rotation, magnetic field, and relaxation times on the speed, attenuation coefficient, and the amplitudes of displacements, temperature, and concentration are displayed graphically.

scholarly journals Origin of conductive surface layer in annealed ZnO

2008 ◽  
Vol 92 (12) ◽  
pp. 122108 ◽  
Author(s):  
D. C. Look ◽  
B. Claflin ◽  
H. E. Smith
Keyword(s):  
Surface Layer ◽  
Conductive Surface

scholarly journals Magnetic field on surface waves propagation in gravitational thermoelastic media with two temperature and initial stress in the context of three theories

2020 ◽  
Vol 24 (Suppl. 1) ◽  
pp. 285-299
Author(s):  
Jamel Bouslimi ◽  
Sayed Abo-Dahab ◽  
Khaled Lotfy ◽  
Sayed Abdel-Khalek ◽  
Eied Khalil ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Surface Waves ◽  
Initial Stress ◽  
Half Space ◽  
Generalized Thermoelasticity ◽  
Phase Lag ◽  
Mathematical Methods ◽  
Numerical Work ◽  
Suitable Material ◽  
Two Temperature

In this paper is investigating the theory of generalized thermoelasticity under two temperature is used to solve boundary value problems of 2-D half-space its bound?ary with different types of heating under gravity effect. The governing equations are solved using new mathematical methods under the context of Lord-Shulman, Green-Naghdi theory of type III (G-N III) and the three-phase-lag model to inves?tigate the surface waves in an isotropic elastic medium subjected to gravity field, magnetic field, and initial stress. The general solution obtained is applied to a spe?cific problem of a half-space and the interaction with each other under the influence of gravity. The physical domain by using the harmonic vibrations is used to obtain the exact expressions for the Waves velocity and attenuation coefficients for Stoneley waves, Love waves, and Rayleigh waves. Comparisons are made with the results between the three theories. Numerical work is also performed for a suitable material with the aim of illustrating the results. The results obtained are calculated numerical?ly and presented graphically with some comparisons in the absence and the presence the influence of gravity, initial stress and magnetic field. It clears that the results ob?tained agree with the physical practical results and agree with the previous results if the gravity, two temperature, and initial stress neglect as special case from this study.

Visualization of the Magnetic Field Distribution for a Direct Current by Using the Magneto-optical Effect

2016 ◽  
Vol 66 (2) ◽  
pp. 231-234
Author(s):  
Sunghoon JEON ◽  
Shant ARAKELYAN ◽  
Yeonsub LEE ◽  
Yongjae KIM ◽  
Hyeji HAN ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Distribution ◽  
Direct Current ◽  
Magnetic Field Distribution ◽  
Optical Effect ◽  
Magneto Optical Effect ◽  
The Magnetic Field
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