Quasi-static magnetic field changes associated with the CANNIKIN nuclear explosion

1972 ◽  
Vol 62 (6) ◽  
pp. 1479-1487 ◽  
Author(s):  
W. P. Hasbrouck ◽  
J. H. Allen
Keyword(s):  
Magnetic Field ◽  
Residual Stresses ◽  
Static Magnetic Field ◽  
Remanent Magnetization ◽  
Nuclear Explosion ◽  
Average Increase ◽  
Ground Zero ◽  
Total Magnetic Field ◽  
Fault Trace ◽  
The Magnetic Field

abstract As a result of the CANNIKIN nuclear explosion, the magnetic field several kilometers from the epicenter appears to have been permanently altered. Within 30 sec after detonation, a proton magnetometer 3 km away recorded a 9-gamma step increase in total magnetic field. Continuous difference recordings between the station at a distance of 3 km from the epicenter and one at 9 km showed that a 7.0-gamma average increase was maintained between these locations for 8 days after the shot. Along a 12-km traverse centered across a portion of a fault 1.6 km from ground zero, postshot-minus-preshot magnetic field difference readings decreased semi-sinusoidally from a high value of +13 gammas in the shot-contained block to a low value of −11 gammas in the distal block. Within 15 m to either side of the fault trace, a 15-gamma wedge-shaped magnetic low was observed. The magnetic effects can be reasonably interpreted as being caused by either shot-produced residual stresses or shot-caused alterations of remanent magnetization.

Effect of a static magnetic field on the preparation of MnOOH and Mn3O4 by a hydrothermal process

RSC Advances ◽  
2016 ◽  
Vol 6 (25) ◽  
pp. 21037-21042 ◽  
Author(s):  
L. C. Dong ◽  
Y. B. Zhong ◽  
S. Zhe ◽  
T. Y. Zheng ◽  
H. Wang
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Static Magnetic Field ◽  
Hydrothermal Process ◽  
Single Crystalline ◽  
20 Nm ◽  
The Magnetic Field

In this paper, the shape of the samples was changed by the magnetic field. Single-crystalline nanowires (20 nm in diameter and 1 μm in length) of MnOOH were obtained under zero magnetic fields. However, cubic particles of Mn3O4 were formed when a magnetic field was applied.

Microstructure and Mechanical Properties of TC4 Titanium Alloy Subjected to High Static Magnetic Field

2017 ◽  
Vol 898 ◽  
pp. 345-354 ◽  
Author(s):  
Gui Rong Li ◽  
Fang Fang Wang ◽  
Hong Ming Wang ◽  
Jiang Feng Cheng
Keyword(s):  
Magnetic Field ◽  
Titanium Alloy ◽  
Dislocation Density ◽  
Static Magnetic Field ◽  
Micro Hardness ◽  
Tc4 Titanium Alloy ◽  
Tc4 Alloy ◽  
Deformation Ability ◽  
Magnetic Induction Intensity ◽  
The Magnetic Field

The TC4 titanium alloy was subjected to high static magnetic field (HSMF) treatment with different magnetic induced intensities (B=0、1T、2T、3T、4T、5T、6T and 7T). The effects of B on the texture, dislocation density, grain size, tensile properties and micro-hardness of TC4 titanium alloy were investigated, and the influence mechanism of magneto-plastic effect on the plastic deformation ability of titanium alloy was also been studied. The results showed that the dislocation density had been increased after the HSME treatment. It reached a maximum when B=2 T, which was enhanced by 1.6 times compared to that of the untreated samples. In the view of quantum scale,the magnetic field promoted the transition of radical pairs from singlet to triplet state, which caused the movement of dislocation, led to the dislocation depinning from the depinning center, and increased the flexibility of dislocation. Subsequently, the inevitability of optimized 2T parameter was further discussed in the dislocation pile-up. Furthermore, the magnetic field not only promoted the orientation preference of crystal plane along the slipping direction, but also had the effect on the grain refinement. Meanwhile the elongation had been increased due to HSMF treatment. The average elongation of TC4 alloy was 13.12% which was enhanced by 31.07% compared to that of the untreated sample which was 10.01%. And, the elongation increased with the increment of magnetic induction intensity B. The HSME treatment could also play a role in hardening alloys. When B=2 T the micro-hardness was 344.88 HV, which was increased by 8.09% compared to that without treatment. The micro-hardness was consistent with the change of the "point" of the dislocation density, which was characterized by dislocation strengthening.

Effect of a Static Magnetic Field (1.5T) on Brain Oscillatory Activities in Resting State Condition

2008 ◽  
Vol 21 (5) ◽  
pp. 629-635 ◽  
Author(s):  
E. Formaggio ◽  
M. Avesani ◽  
S.F. Storti ◽  
F. Milanese ◽  
A. Gasparini ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Alpha Power ◽  
Eeg Signal ◽  
Eyes Closed ◽  
Prime Concern ◽  
Eeg Data ◽  
Significant Difference ◽  
Eyes Open ◽  
The Magnetic Field

The aim of the present study was to compare the EEG signal recorded outside and inside a 1.5T magnetic resonance (MR) scanner. The EEG was recorded in eyes open and eyes closed conditions using a digital recording MR-compatible system. To characterize how a static magnetic field induces changes in EEG signal, EEG data were analyzed using FFT frequency analysis. No significant difference between the alpha powers recorded outside and inside the magnetic field was observed in eyes closed conditions. However, in eyes open condition there was a significant increase in alpha power inside the magnet in comparison to the outside position. The changes in alpha power according to the eyes open/closed conditions could be inversely correlated to a subject's state of wakefulness and due to some physiological changes, rather than an effect of the magnetic field. This experiment suggests that subjects' state of wakefulness is of prime concern when performing functional MRI.

scholarly journals Modeling magnetostratigraphy in a borehole

Geophysics ◽  
1989 ◽  
Vol 54 (8) ◽  
pp. 973-983 ◽  
Author(s):  
Yves Gallet ◽  
Vincent Courtillot
Keyword(s):  
Magnetic Field ◽  
Remanent Magnetization ◽  
Operation Mode ◽  
Resolving Power ◽  
Vertical Profiles ◽  
Rock Property ◽  
Hole Radius ◽  
Differential Operation ◽  
Vector Magnetometer ◽  
The Magnetic Field

The magnetic field along a hole bored through a sequence of dipping layers with varying magnetization and planar interfaces is calculated. The emphasis is on recovering remanent magnetization polarity transitions for magnetostratigraphic applications (dating, correlations), although intensity of remanent magnetization can in itself be a useful rock property. Results are presented for various cases of geologic interest in the form of axial vertical profiles and section maps of the holes at varying distances from polarity reversal interfaces. The vertical profiles demonstrate a resolving power of about six times the hole radius; meaningful magnetostratigraphies can be expected for rocks with a magnetization larger than [Formula: see text], for instruments with a sensitivity of 0.1 nT. In a number of natural occurrences, it may not be necessary to resort to progressive demagnetization to recover the polarity sequence. Depending on which magnetic field and magnetization component one looks at, the section maps display characteristic patterns, in which, for instance, the direction of magnetization and the dip of the layers interfere. These maps are discussed in some detail. They can be used as guidelines to build a multisensor vector magnetometer (downhole magnetostratigraphic tool), whose output should be coupled with measurement of magnetic susceptibility for reduction of induced magnetization and with output from a surface instrument in a differential operation mode to reduce transient magnetic variations.

Research and Design for Three-Axis Electromagnetic Leakage Detector

2012 ◽  
Vol 241-244 ◽  
pp. 223-226
Author(s):  
Jiang Shan Qian ◽  
Zhong Ran Zhou ◽  
Yu Wang ◽  
Tong Guang Shao ◽  
Jin Bo Zhang
Keyword(s):  
Magnetic Field ◽  
Electromagnetic Coupling ◽  
Low Frequency ◽  
Electrical Equipment ◽  
Electronic Products ◽  
Total Magnetic Field ◽  
Leakage Magnetic Field ◽  
Measurement Experiment ◽  
Research And Design ◽  
The Magnetic Field

In order to measure the magnetic field around electronic products, household appliances and industrial electrical equipment, this paper puts forward a new method which makes use of electromagnetic coupling design based on three-axis electromagnetic leakage. This method can overcome the disadvantage of traditional single-axis measurement which needs to get the total magnetic field after several times’ measurement. This paper designs three-axis electromagnetic leakage detector for circuit measurement, which is proved to be correct after circuit measurement experiment. It can easily detect 30-2K Hz leakage magnetic field of low frequency generated from electrical appliances products.Introduction.

Fabrication of c-axis oriented polycrystalline ZnO by using a rotating magnetic field and following sintering

2006 ◽  
Vol 21 (3) ◽  
pp. 703-707 ◽  
Author(s):  
Satoshi Tanaka ◽  
Atsushi Makiya ◽  
Zenji Kato ◽  
Nozomu Uchida ◽  
Tsunehisa Kimura ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Crystal Form ◽  
Rotating Magnetic Field ◽  
Field Control ◽  
Degree Of Orientation ◽  
Oriented Polycrystalline ◽  
The Magnetic Field ◽  
Zno Ceramics ◽  
Functional Ceramics

We succeeded in fabricating c-axis (00l) oriented ZnO ceramics by using a rotating magnetic field and a subsequent sintering treatment. The degree of orientation in the green compact was about 0.5 along (00l) on the Lotgering scale. The degree of orientation increased to 0.99 after sintering at 1573 K. Particles can also be oriented in a static magnetic field, but along the direction of the a-axis or a,b-axes (h00), (hk0). These results show that selected axes can be oriented by controlling the magnetic field. Control of the crystal form in microstructures is expected to result in improvements in and better miniaturization of functional ceramics.

ELECTROMAGNETIC WAVES IN A BOUNDED, ANISOTROPIC PLASMA

1962 ◽  
Vol 40 (7) ◽  
pp. 887-905 ◽  
Author(s):  
K. A. Graf ◽  
M. P. Bachynski
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Electromagnetic Waves ◽  
Plane Electromagnetic Wave ◽  
Plasma Boundary ◽  
Plasma Properties ◽  
Magnetic Field Data ◽  
Reflected Waves ◽  
Quartic Equation ◽  
The Magnetic Field

The interaction of a plane, electromagnetic wave with a flat, uniform free-space – plasma interface in a static magnetic field has been considered for arbitrary angles of incidence. The dispersion relation for the plasma is a complex quartic equation which reduces to a quadratic if the static magnetic field and plasma boundary are oriented along any one of the rectangular co-ordinate axes. (These axes need not simultaneously be the same for the plasma and the magnetic field.)Numerical results are presented for the attenuation and phase constants for each of the two possible waves in the plasma, for each orientation of the static magnetic field. Data are given for various angles of incidence, plasma properties, and orientations of the static magnetic field relative to the plasma boundary.Inspection of the fields in the plasma reveals some interesting aspects. In certain cases, waves which appear to move upward towards the plasma interface exist. Since these waves may carry energy into the plasma, they have been referred to as "backward" waves. Totally reflected waves which have both finite attenuation and finite phase coefficients can also exist in the plasma. These have been termed "modified Sommerfeld" waves.

scholarly journals Orientation of erythrocytes in a strong static magnetic field

Blood ◽  
1993 ◽  
Vol 82 (4) ◽  
pp. 1328-1334 ◽  
Author(s):  
T Higashi ◽  
A Yamagishi ◽  
T Takeuchi ◽  
N Kawaguchi ◽  
S Sagawa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Magnetic Levitation ◽  
Diagnostic Technique ◽  
The Body ◽  
Transport Systems ◽  
Magnetic Field Direction ◽  
Disk Plane ◽  
Degree Of Orientation ◽  
The Magnetic Field

Abstract The frequency of exposure to strong magnetic fields has increased as the magnetic-resonance image-diagnostic technique (MRI) and passenger transport systems based on the principle of magnetic levitation have come into wider use. Accordingly, it has become necessary to more systematically assess their influence on the body and set strict guidelines on acceptable limits of magnetism exposure. Therefore, we have assessed the influence of an uniform static magnetic field (8 T in maximum) on normal erythrocytes. The erythrocytes were oriented with their disk plane parallel to the magnetic field direction. These erythrocytes were influenced even by 1 T and almost 100% of them were oriented when exposed to 4 T. Furthermore, the degree of orientation was not influenced by the state of hemoglobin (oxy: diamagnetic, deoxy and met: paramagnetic). The dependence of the measured degree of orientation on the intensity of the magnetic field was in good agreement with the theoretical equation for the magnetic orientation of diamagnetic substances. As a result of a numerical analysis based on the equation, the anisotropic diamagnetic susceptibility of erythrocytes was found to be delta chi = 8 x 10(-22) electromagnetic units/erythrocyte. It was almost in agreement with the calculated value delta chi = 6 x 10(-22) emu/erythrocyte estimated from the diamagnetism of the membrane constituents of erythrocyte.

Effect of static magnetic field on the helical flow of incompressible cholesteric liquid crystal between two coxial circular cylinders having rotational and axial velocities

1976 ◽  
Vol 19 (3) ◽  
pp. 371-380
Author(s):  
G. Paria ◽  
A. K. Sharma
Keyword(s):  
Magnetic Field ◽  
Liquid Crystal ◽  
Angular Velocity ◽  
Static Magnetic Field ◽  
Axial Velocity ◽  
Cholesteric Liquid Crystal ◽  
Helical Flow ◽  
Circular Cylinders ◽  
The Magnetic Field ◽  
Orientation Of Molecules

AbstractThe paper investigates the effect of a static magnetic field on the helical flow of an incompressible cholestenc liquid crystal with director of unit magnitude between two coaxial circular cylinders rotating with different angular velocities about their common axis and moving with different axial velocities. At low shear rates with a weak magnetic field in the axial direction, the axial velocity, the angular velocity and the orientation of molecules between the two cylinders have been obtained. It is found that the magnetic field has influenced the orientation of molecules while the axial velocity and the angular velocity remain uneffected by the magnetic field.

Mitigating remanent magnetization effects in magnetic data using the normalized source strength

Geophysics ◽  
2013 ◽  
Vol 78 (3) ◽  
pp. J25-J32 ◽  
Author(s):  
Mark Pilkington ◽  
Majid Beiki
Keyword(s):  
Magnetic Field ◽  
Remanent Magnetization ◽  
Field Data ◽  
Magnetic Data ◽  
Magnetization Distribution ◽  
Source Strength ◽  
Inversion Algorithm ◽  
Data Set ◽  
Magnetic Field Data ◽  
The Magnetic Field

We have developed an approach for the interpretation of magnetic field data that can be used when measured anomalies are affected by significant remanent magnetization components. The method deals with remanent effects by using the normalized source strength (NSS), a quantity calculated from the eigenvectors of the magnetic gradient tensor. The NSS is minimally affected by the direction of remanent magnetization present and compares well with other transformations of the magnetic field that are used for the same purpose. It therefore offers a way of inverting magnetic data containing the effects of remanent magnetizations, particularly when these are unknown and are possibly varying within a given data set. We use a standard 3D inversion algorithm to invert NSS data from an area where varying remanence directions are apparent, resulting in a more reliable image of the subsurface magnetization distribution than possible using the observed magnetic field data directly.

Sign in / Sign up

Export Citation Format

Share Document