Magnetohydrodynamic Disturbances due to the Sudden Introduction of a Magnetic Dipole in a Fluid of Finite Conductivity.

1959 ◽  
Vol 129 ◽  
pp. 172 ◽  
Author(s):  
M. G. S. El Mohandis
Keyword(s):  
Magnetic Dipole ◽  
Finite Conductivity ◽  
Sudden Introduction

RESPONSE OF THIN DYKE TO OSCILLATING DIPOLE

Geophysics ◽  
1958 ◽  
Vol 23 (1) ◽  
pp. 134-143 ◽  
Author(s):  
James Paul Wesley
Keyword(s):  
Exact Solution ◽  
Magnetic Dipole ◽  
Analytical Continuation ◽  
Dipole Source ◽  
Finite Conductivity ◽  
First Approximation ◽  
Sulfide Ore ◽  
Infinite Slab ◽  
Infinite Conductivity

A dyke of sulfide ore may be geophysically prospected by observing its response to a slowly oscillating magnetic dipole source. To a first approximation the field produced by a thin dyke is given by a dyke of infinite conductivity and vanishing thickness in a vacuum (Wesley, 1958, Geophysics, v. 23, p. 128). In order to identify the ore and to estimate the size of the deposit, it is necessary to consider further approximations involving the conductivity and thickness of the dyke. By a type of analytical continuation an approximation is found which agrees both with the exact solution for a dyke of infinite conductivity and vanishing thickness and with the exact solution (approximated only for ωσ large and also for σ small) for an infinite slab of finite conductivity and nonvanishing thickness, the dyke appearing as an infinite slab when both source and observer are near the dyke but far removed from the edge. The solution is very good provided the dyke is geometrically thin.

Braking of a magnetic dipole moving with an arbitrary velocity through a conducting pipe

2006 ◽  
Vol 176 (9) ◽  
pp. 965
Author(s):  
B.A. Knyazev ◽  
I.A. Kotel'nikov ◽  
A.A. Tyutin ◽  
V.S. Cherkasskii
Keyword(s):  
Magnetic Dipole ◽  
Arbitrary Velocity

scholarly journals Calibration of Radiocarbon Dates for the Late Pleistocene Using U/Th Dates on Stalagmites

Radiocarbon ◽  
1997 ◽  
Vol 39 (1) ◽  
pp. 27-32 ◽  
Author(s):  
John C. Vogel ◽  
Joel Kronfeld
Keyword(s):  
South Africa ◽  
Magnetic Dipole ◽  
Satisfactory Agreement ◽  
Late Pleistocene ◽  
Calibration Curve ◽  
Dipole Field ◽  
Radiocarbon Dates ◽  
The Past ◽  
The Earth ◽  
Magnetic Dipole Field

Twenty paired 14C and U/Th dates covering most of the past 50,000 yr have been obtained on a stalagmite from the Cango Caves in South Africa as well as some additional age-pairs on two stalagmites from Tasmania that partially fill a gap between 7 ka and 17 ka ago. After allowance is made for the initial apparent 14C ages, the age-pairs between 7 ka and 20 ka show satisfactory agreement with the coral data of Bard et al. (1990, 1993). The results for the Cango stalagmite between 25 ka and 50 ka show the 14C dates to be substantially younger than the U/Th dates except at 49 ka and 29 ka, where near correspondence occurs. The discrepancies may be explained by variations in 14C production caused by changes in the magnetic dipole field of the Earth. A tentative calibration curve for this period is offered.

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