Reverse-magnetic-field reciprocity in conductive samples with extended contacts

2008 ◽  
Vol 104 (2) ◽  
pp. 024505 ◽  
Author(s):  
Martin Cornils ◽  
Oliver Paul
Keyword(s):  
Magnetic Field ◽  
Reverse Magnetic Field

THE DESIGN OF EDDY-CURRENT MAGNET BRAKES

2011 ◽  
Vol 35 (1) ◽  
pp. 19-37 ◽  
Author(s):  
Der-Ming Ma ◽  
Jaw-Kuen Shiau
Keyword(s):  
Magnetic Field ◽  
Field Distribution ◽  
Eddy Current ◽  
Constant Magnetic Field ◽  
Design Procedure ◽  
Magnetic Field Distribution ◽  
Piecewise Constant ◽  
Braking System ◽  
Potential Applications ◽  
Reverse Magnetic Field

The eddy-current is created by the relative motion between a magnet and a metal (or alloy) conductor. The current induces the reverse magnetic field and results in the deceleration of motion. The proposed mechanism implements this phenomenon in developing a braking system. The potential applications of the braking system can be a decelerating system to increase the safety of an elevator or any guided rail transportation system. To provide scientific investigation for industrial application of magnetic braking, this study presents four systematic engineering design scenarios to design a braking system. The constant magnetic field is the simplest and easiest design to implement. The optimal magnetic field distribution is obtained by minimizing the deceleration effort. The piecewise-constant magnetic field distribution offers a compromise between performance and magnetic field requirements. The advantages of the section-wise guide rail are tolerable deceleration; and simple design requirement and manufacturing processes. In the study, an experimental braking system using constant magnetic field is build to demonstrate the design procedure.

Transient loss from a theta pinch with an initial trapped reverse magnetic field

1982 ◽  
Vol 24 (10) ◽  
pp. 1243-1260 ◽  
Author(s):  
J E Heidrich ◽  
T M York ◽  
J W Robinson ◽  
E H Klevans
Keyword(s):  
Magnetic Field ◽  
Theta Pinch ◽  
Transient Loss ◽  
Reverse Magnetic Field

scholarly journals Magnetostrictive Blocked-Force Clamping Mechanism for Secure and Heavy-Load Inchworm Motion

2009 ◽  
Author(s):  
B. T. Yang ◽  
G. Meng ◽  
P. Y. Xu ◽  
X. T. Tan ◽  
Z. Q. Feng ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Smart Materials ◽  
Clamping Force ◽  
Working Process ◽  
Heavy Load ◽  
Precise Positioning ◽  
Giant Magnetostriction ◽  
Reverse Magnetic Field ◽  
Direction Field

The capability of inchworm motor for long-displacement, heavy-load and precise positioning is greatly conditioned by the effectiveness of the clamping mechanism. A need exists in the art for clamping mechanism capable of delivering precise and heavy load motion. This paper presents a novel giant magnetostriction material (GMM) application to the development of such mechanism. GMM is advantageous over other smart materials in this particular aspect by its remarkable magnetostriction and especially the huge blocked stress. It can, e.g., display around 4000N at moderate magnetization with a φ25×100mm GMM rod. Most desirably, such large force could be used as clamping force in inchworm movement. However, the force can only be generated under blocked state, which is generally hard to reach, especially in a moving regime. Addressing this problem, the research utilizes GMM rod’s capacity to both positively stretch and negatively contract under permanent-magnet-biased condition and presents a specially designed clamping mechanism, a permanent-magnet-biased actuator fastened in a rigid guideway. Being applied reverse magnetic field, the formerly stretched actuator may contract to a suitable size to be put into the rigid guideway. Then, removal of the field will theoretically result in the restoration of the actuator. Practically, stretching of the actuator is blocked by the rigid guideway. This forms the so-called Pre-blocked-clamping-on state, where no-power fastening behavior exists. Moreover, the blocked force is adjustable. When being applied the same-direction field as the permanent one, the blocked force becomes greater (Blocked-clamping-on state). When being applied adequate reverse field, the blocked force is diminished with the shrinking of the actuator, till the actuator released from the rails (Blocked-clamping-off state). This process realizes the utilization of blocked force in clamping action, thus provides resolution for secure and heavy load inchworm motion. A clamping mechanism prototype (Size:φ32×130mm, with a φ10×100mm GMM rod) has been realized. The design and working process of the setup is presented. Through experiments, the prototype can be facilely manipulated by square-instant and sinusoid-continuing current and it can agilely perform to meet the proposed blocked force the proposed clamping principle.

Experiment on the use of an auxiliary discharge to investigate plasma properties in a theta pinch with a trapped reverse magnetic field

1963 ◽  
Vol 3 (4) ◽  
pp. 285-292 ◽  
Author(s):  
I.F. Kvartskhava ◽  
K.N. Kervalidze ◽  
G.G. Zukakishvili ◽  
Yu.S. Gvaladze
Keyword(s):  
Magnetic Field ◽  
Plasma Properties ◽  
Theta Pinch ◽  
Reverse Magnetic Field

Magnetic-field strengths from optical polarization data

1967 ◽  
Vol 31 ◽  
pp. 381-383
Author(s):  
J. M. Greenberg
Keyword(s):  
Magnetic Field ◽  
Optical Polarization ◽  
Polarization Data ◽  
Term Model ◽  
Source Of Information ◽  
Field Strengths

Van de Hulst (Paper 64, Table 1) has marked optical polarization as a questionable or marginal source of information concerning magnetic field strengths. Rather than arguing about this–I should rate this method asq+-, or quarrelling about the term ‘model-sensitive results’, I wish to stress the historical point that as recently as two years ago there were still some who questioned that optical polarization was definitely due to magnetically-oriented interstellar particles.

Observing the galactic magnetic field

1967 ◽  
Vol 31 ◽  
pp. 375-380
Author(s):  
H. C. van de Hulst
Keyword(s):  
Magnetic Field ◽  
Fair Agreement ◽  
Solar Neighbourhood ◽  
Galactic Magnetic Field ◽  
The Magnetic Field

Various methods of observing the galactic magnetic field are reviewed, and their results summarized. There is fair agreement about the direction of the magnetic field in the solar neighbourhood:l= 50° to 80°; the strength of the field in the disk is of the order of 10-5gauss.

Structure in the radiation of the galactic disk

1967 ◽  
Vol 31 ◽  
pp. 355-356
Author(s):  
R. D. Davies
Keyword(s):  
Magnetic Field ◽  
Galactic Disk ◽  
Galactic Magnetic Field ◽  
Measured Polarization

Observations at various frequencies between 136 and 1400 MHz indicate a considerable amount of structure in the galactic disk. This result appears consistent both with measured polarization percentages and with considerations of the strength of the galactic magnetic field.

Calculated Coronal Magnetic Fields and Their Comparison with the Coronal Structures as Observed during Five Solar Eclipses

1994 ◽  
Vol 144 ◽  
pp. 559-564
Author(s):  
P. Ambrož ◽  
J. Sýkora
Keyword(s):  
Magnetic Field ◽  
Solar Cycle ◽  
Magnetic Fields ◽  
Solar Corona ◽  
Coronal Magnetic Field ◽  
Coronal Magnetic Fields ◽  
Solar Eclipses ◽  
Coronal Structures

AbstractWe were successful in observing the solar corona during five solar eclipses (1973-1991). For the eclipse days the coronal magnetic field was calculated by extrapolation from the photosphere. Comparison of the observed and calculated coronal structures is carried out and some peculiarities of this comparison, related to the different phases of the solar cycle, are presented.

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