scholarly journals Nonlinear Oscillations Current Carry Orthotropic Shell in a Magnetic Field

2013 ◽  
Vol 03 (04) ◽  
pp. 318-321
Author(s):  
Indiaminov Ravshan Shukurovich
Keyword(s):  
Magnetic Field ◽  
Nonlinear Oscillations ◽  
Orthotropic Shell ◽  
Current Carry

INFLUENCE OF THE MAGNETIC FIELD ON THE TRANSVERSE RUNAWAY THRESHOLD

2007 ◽  
Vol 21 (10) ◽  
pp. 1715-1720 ◽  
Author(s):  
NANA METREVELI ◽  
ZAUR KACHLISHVILI ◽  
BEKA BOCHORISHVILI
Keyword(s):  
Magnetic Field ◽  
Electric Field ◽  
Electric Fields ◽  
Applied Electric Field ◽  
Nonlinear Oscillations ◽  
Hot Electrons ◽  
Total Field ◽  
Practical Applications ◽  
Energy And Momentum ◽  
The Magnetic Field

The transverse runaway (TR) is a phenomenon whereby for a certain combination of energy and momentum scattering mechanisms of hot electrons, and for a certain threshold of the applied electric field, the internal (total) field tends to infinity. In this work, the effect of the magnetic field on the transverse runaway threshold is considered. It is shown that with increasing magnetic field, the applied critical electric fields relevant to TR decrease. The obtained results are important for practical applications of the TR effect as well as for the investigation of possible nonlinear oscillations that may occur near the TR threshold.

scholarly journals Nonlinear Deformation of Flexible Orthotropic Shells of Variable Thickness in an Unsteady Magnetic Field

2019 ◽  
Vol 97 ◽  
pp. 02015 ◽  
Author(s):  
Zafar Abdullaev ◽  
Sayibdjan Mirzaev ◽  
Sobir Mavlanov
Keyword(s):  
Magnetic Field ◽  
Stress State ◽  
Electric Current ◽  
Variable Thickness ◽  
Nonlinear Deformation ◽  
Strain State ◽  
Orthotropic Shell ◽  
Mechanical Force ◽  
Time Varying ◽  
Orthotropic Shells

The analysis of the stress state of a flexible orthotropic shell under the influence of a time-varying mechanical force and a time-varying external electric current is performed, taking into account the mechanical and electromagnetic orthotropy. The effect of thickness on the stress-strain state of the orthotropic shell is investigated. The results obtained indicate the influence of thickness on the deformation of the shell and the need to take this factor into account in the design schemes.

Study of Energy Methods to Strongly Nonlinear Vibrations in a Loudspeaker Cone-Shaped Shell

2005 ◽  
Author(s):  
F. D. Zong ◽  
Z. L. Zhang ◽  
J. W. Fang ◽  
Y. J. Yu ◽  
Q. Chen
Keyword(s):  
Magnetic Field ◽  
Limit Cycles ◽  
Nonlinear Oscillations ◽  
Low Frequency ◽  
Approximate Solutions ◽  
Energy Methods ◽  
Frequency Range ◽  
Strongly Nonlinear ◽  
Harmonic Vibrations ◽  
Strongly Nonlinear Oscillations

H. F. Olson points out that a loudspeaker cone-shaped shell, as a nonlinear oscillation system, can be described as the Classical Duffing Equation in low frequency range. Yoshinisa, a Japanese scholar, studied the nonlinear phenomena of the loudspeaker cone-shaped shell in low frequency range driven by a stable galvanic source, including the resonance frequency changing with amplitude and leap phenomena. But their research were not taken the influence of nonlinear magnetic field into account. Its work mostly related to getting solution of nonlinear differential equation by the Numerical Calculation, but it didn’t get approximate solutions. Through research and analysis of the experiment on the loudspeaker cone-shaped shell, we obtain the Generalized Duffing Equation that’s a strongly nonlinearity system which is used to describe the loudspeaker cone-shaped shell driven by a stable voltage source, it considers the nonlinearity of mechanical resilience and the magnetic field. This paper focuses on first finding the approximate solutions (limit cycles) of strongly nonlinear oscillations and nonlinear heteronomy of the loudspeaker cone-shaped shell in low frequency range by use of energy methods. They obtained the equation relating to the forced vibration amplitude with frequency and the corresponding relation about phase versus frequency, and analysed particularly complete stability of limit cycles belonged to the strongly nonlinear systems, and drew several important conclusions. (1) As to strongly nonlinear oscillations of the loudspeaker cone-shaped shell in low frequency range, it is only likely to appear main oscillation and odd-order sub-harmonic oscillations. But it cannot appear super-harmonic vibrations and even-order sub-harmonic vibrations. (2) As to strongly nonlinear oscillations of the loudspeaker cone-shaped shell in low frequency range, two cases about main oscillation and one third sub-harmonic oscillation whose approximate solutions accord with numerical solutions very well. (3) It is worthy to study strongly nonlinear oscillations of commonly thin shell structure such as a loudspeaker cone-shaped shell by use of energy methods, and we will continue to carry out this research.

scholarly journals Nonlinear Evolution of the Parker Instability

1991 ◽  
Vol 144 ◽  
pp. 429-432
Author(s):  
R. Matsumoto ◽  
K. Shibata
Keyword(s):  
Magnetic Field ◽  
Equatorial Plane ◽  
Nonlinear Evolution ◽  
Nonlinear Oscillations ◽  
Unstable Mode ◽  
Loop Length ◽  
Two Dimensional ◽  
Mhd Simulations ◽  
Field Lines ◽  
Half Thickness

Two-dimensional MHD simulations are performed to study the nonlinear evolution of the Parker instability in galactic gas disks. When the most unstable mode grows, magnetic field lines kink across the equatorial plane of the disk and thin spur-like structures are formed above dense regions in magnetic pockets. In low β (= ρgas/ρmag < 3) disks, shock waves are produced at the footpoint of magnetic loops, while in high β (> 3) disks, nonlinear oscillations are excited and the loop length increases with time up to λc ≃ (3.5β + 6)H, where H is the half-thickness of the disk.

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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