Demagnetizing Experiment of Magnetism-Concealed Tank Based on Smart Materials

2014 ◽  
Vol 484-485 ◽  
pp. 151-156
Author(s):  
Ying Huang
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Smart Materials ◽  
Design Method ◽  
Earth Magnetic Field ◽  
Experiment Method ◽  
Auxiliary Experiment ◽  
Protection Theory ◽  
The Right ◽  
Train Of Thought

The core component -----a set of coaxial densely winded degaussing loops of a magnetism-concealed tank is designed and made by experiment method. From the data, it can be concluded that the coaxial densely winded degaussing loops can eliminate the tanks magnetic field signs which are engendered by magnetization in the earth magnetic field, specially, the demagnetizing effect near the axis is more obvious. It should be paid attention to the direction of the demagnetizing electric current in experimentation, another important factor to get optimal demagnetizing effect is to seize the right time of demagnetizing electric current. If a demagnetizing electric current is kept too long, as can be seen from the table, the tanks magnetic field signs will be strengthened owing to the counter-rotational magnetization, which accords with the electromagnetic theories. In addition, the degaussing loops work characteristics are given in our auxiliary experiment. In conclusion this experiment design method provides a sustain for magnetism protection theory of equips, and a train of thought is offered for both the magnetism-concealed tanks designing and researching through the experiment process.

scholarly journals Null Effect of Transcranial Static Magnetic Field Stimulation over the Dorsolateral Prefrontal Cortex on Behavioral Performance in a Go/NoGo Task

2021 ◽  
Vol 11 (4) ◽  
pp. 483
Author(s):  
Tatsunori Watanabe ◽  
Nami Kubo ◽  
Xiaoxiao Chen ◽  
Keisuke Yunoki ◽  
Takuya Matsumoto ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Prefrontal Cortex ◽  
Inhibitory Control ◽  
Static Magnetic Field ◽  
Dorsolateral Prefrontal Cortex ◽  
Cortical Excitability ◽  
Control Function ◽  
Field Stimulation ◽  
Dorsolateral Prefrontal ◽  
The Right

The purpose of this pilot study was to investigate whether transcranial static magnetic field stimulation (tSMS), which can modulate cortical excitability, would influence inhibitory control function when applied over the dorsolateral prefrontal cortex (DLPFC). Young healthy adults (n = 8, mean age ± SD = 24.4 ± 4.1, six females) received the following stimulations for 30 min on different days: (1) tSMS over the left DLPFC, (2) tSMS over the right DLPFC, and (3) sham stimulation over either the left or right DLPFC. The participants performed a Go/NoGo task before, immediately after, and 10 min after the stimulation. They were instructed to extend the right wrist in response to target stimuli. We recorded the electromyogram from the right wrist extensor muscles and analyzed erroneous responses (false alarm and missed target detection) and reaction times. As a result, 50% of the participants made erroneous responses, and there were five erroneous responses in total (0.003%). A series of statistical analyses revealed that tSMS did not affect the reaction time. These preliminary findings suggest the possibility that tSMS over the DLPFC is incapable of modulating inhibitory control and/or that the cognitive load imposed in this study was insufficient to detect the effect.

scholarly journals Magnetoactive elastomers for magnetically tunable vibrating sensor systems

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tatiana I. Becker ◽  
Yuriy L. Raikher ◽  
Oleg V. Stolbov ◽  
Valter Böhm ◽  
Klaus Zimmermann
Keyword(s):  
Magnetic Field ◽  
Steady State ◽  
Smart Materials ◽  
Excitation Frequency ◽  
Experimental Studies ◽  
Uniform Field ◽  
Sensor Systems ◽  
Ongoing Research ◽  
Amplification Ratio ◽  
Field Distortion

Abstract Magnetoactive elastomers (MAEs) are a special type of smart materials consisting of an elastic matrix with embedded microsized particles that are made of ferromagnetic materials with high or low coercivity. Due to their composition, such elastomers possess unique magnetic field-dependent material properties. The present paper compiles the results of investigations on MAEs towards an approach of their potential application as vibrating sensor elements with adaptable sensitivity. Starting with the model-based and experimental studies of the free vibrational behavior displayed by cantilevers made of MAEs, it is shown that the first bending eigenfrequency of the cantilevers depends strongly on the strength of an applied uniform magnetic field. The investigations of the forced vibration response of MAE beams subjected to in-plane kinematic excitation confirm the possibility of active magnetic control of the amplitude-frequency characteristics. With change of the uniform field strength, the MAE beam reveals different steady-state responses for the same excitation, and the resonance may occur at various ranges of the excitation frequency. Nonlinear dependencies of the amplification ratio on the excitation frequency are obtained for different magnitudes of the applied field. Furthermore, it is shown that the steady-state vibrations of MAE beams can be detected based on the magnetic field distortion. The field difference, which is measured simultaneously on the sides of a vibrating MAE beam, provides a signal with the same frequency as the excitation and an amplitude proportional to the amplitude of resulting vibrations. The presented prototype of the MAE-based vibrating unit with the field-controlled “configuration” can be implemented for realization of acceleration sensor systems with adaptable sensitivity. The ongoing research on MAEs is oriented to the use of other geometrical forms along with beams, e.g. two-dimensional structures such as membranes.

scholarly journals The effect of simplifications of a numerical mesh on the results of electromagnetic analysis of the Nuclotron-type cable

2018 ◽  
Vol 177 ◽  
pp. 08004
Author(s):  
Łukasz Tomków
Keyword(s):  
Magnetic Field ◽  
Electric Current ◽  
Current Density ◽  
Electric Current Density ◽  
Electromagnetic Analysis ◽  
First Case ◽  
Single Region ◽  
The Magnetic Field

The model of a single Nuclotron-type cable is presented. The goal of this model is to assess the behaviour of the cable under different loads. Two meshes with different simplifications are applied. In the first case, the superconductor in the cable is modelled as single region. Second mesh considers individual strands of the cable. The significant differences between the distributions of the electric current density obtained with both models are observed. The magnetic field remains roughly similar.

scholarly journals DESIGN CONCEPT OF TEST STAND FOR DETERMINING PROPERTIES OF MAGNETORHEOLOGICAL ELASTOMERS

2013 ◽  
Vol 7 (3) ◽  
pp. 131-134 ◽  
Author(s):  
Mirosław Bocian ◽  
Jerzy Kaleta ◽  
Daniel Lewandowski ◽  
Michał Przybylski
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Smart Materials ◽  
Vibration Damping ◽  
Test Stand ◽  
Design Concept ◽  
Special Test ◽  
Magnetorheological Elastomers ◽  
Vibration Dampers

Abstract Magnetorheological elastomers (MRE) are “SMART” materials that change their mechanical properties under influence of magnetic field. Thanks to that ability it is possible to create adaptive vibration dampers based on the MRE. To test vibration damping abilities of this material special test stand is required. This article presents design concept for such test stand with several options of testing.

SIMULATION OF NONLINEAR MAGNETORHEOLOGICAL PARTICLE-FILLED ELASTOMERS

2013 ◽  
Vol 02 (03n04) ◽  
pp. 1350018
Author(s):  
SHULEI SUN ◽  
XIONGQI PENG ◽  
ZAOYANG GUO
Keyword(s):  
Magnetic Field ◽  
Shear Modulus ◽  
Young’S Modulus ◽  
Applied Magnetic Field ◽  
Smart Materials ◽  
Young's Modulus ◽  
Particle Volume ◽  
Magnetorheological Elastomers ◽  
Maxwell Stress Tensor ◽  
Element Simulation

Polymer matrix filled with ferromagnetic particles is a class of smart materials whose mechanical properties can be changed under different magnetic field. They are usually referred to as magnetorheological elastomers (MREs). A finite element simulation was presented to describe the mechanical behavior of MREs with the nonlinearity of the particle magnetization being incorporated. By introducing the Maxwell stress tensor, a representative volume element (RVE) was proposed to calculate the Young's modulus and shear modulus of MREs due to the applied magnetic field. The influences of the applied magnetic field and the particle volume fractions in the shear modulus and Young's modulus were studied. Results show that the shear modulus increases with the magnitude of the applied magnetic field, while the Young's modulus decreases.

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