scholarly journals Study of Friction Force in Electrodynamic Rail Accelerator: Experiment and Interpretation Using FEM Modelling

Physics ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 596-607
Author(s):  
Tomáš Tichý ◽  
Jan Zemen ◽  
Libor Dražan ◽  
František Racek ◽  
Václav Papež ◽  
...  

The paper presents experimental data and a model of an electromagnetic rail accelerator. The model includes an equivalent circuit, magnetic field in the system and movement of the projectile (that is solved separately) which is computed numerically. The main results are compared with our experimental data and friction force during acceleration is evaluated.

Actuators ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 74
Author(s):  
Tsam Lung You ◽  
Hemma Philamore ◽  
Fumitoshi Matsuno

In this work we present a soft crawler fabricated using a magneto-active elastomer. The crawler is controlled by an external magnetic field to produce two locomotion patterns: peristaltic and caterpillar crawling. Due to its structural simplicity, low mass, wirelessly controlled actuation and compliant body the design of this crawler has the potential to address the key challenges faced by existing crawling robots. Experimental data were gathered to evaluate the performance of the crawler locomotion in a pipe. The results validated the mathematical models proposed to estimate the distance traveled by the crawler. The crawler shows potential for use in exploration of confined spaces.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Suchitra Rajput ◽  
Sujeet Chaudhary

We report on the analyses of fluctuation induced excess conductivity in the - behavior in the in situ prepared MgB2 tapes. The scaling functions for critical fluctuations are employed to investigate the excess conductivity of these tapes around transition. Two scaling models for excess conductivity in the absence of magnetic field, namely, first, Aslamazov and Larkin model, second, Lawrence and Doniach model, have been employed for the study. Fitting the experimental - data with these models indicates the three-dimensional nature of conduction of the carriers as opposed to the 2D character exhibited by the HTSCs. The estimated amplitude of coherence length from the fitted model is ~21 Å.


2021 ◽  
Vol 141 (11) ◽  
pp. 606-614
Author(s):  
Jiaqing Wang ◽  
Ken Kawamata ◽  
Shinobu Ishigami ◽  
Takeshi Ishida ◽  
Osamu Fujiwara

2009 ◽  
Vol 152-153 ◽  
pp. 373-376 ◽  
Author(s):  
Stanislav O. Volchkov ◽  
Andrey V. Svalov ◽  
G.V. Kurlyandskaya

In this work magnetoimpedance (MI) behaviour was studied experimentally for Fe19Ni81(175 nm)/Cu(350 nm)/Fe19Ni81(175 nm) sensitive elements deposited by rf-sputtering. A constant magnetic field was applied in plane of the sandwiches during deposition perpendicular to the Cu-lead in order to induce a magnetic anisotropy. Sandwiches with different width (w) of FeNi parts were obtained. The complex impedance was measured as a function of the external magnetic field for a frequency range of 1 MHz to 700 MHz for MI elements with different geometries. Some of MI experimental data are comparatively analysed with finite elements numerical calculations data. The obtained results can be useful for optimization of the design of miniaturized MI detectors.


2019 ◽  
Vol 945 ◽  
pp. 771-775 ◽  
Author(s):  
V.P. Panaetov ◽  
Denis B. Solovev

Ferromagnetic film can be a matrix for recording information with the help of magnetic moments of electrons. The study of the processes of changing the magnetic structure in an electron-transmission microscope makes it possible to investigate micro magnetic phenomena. In this paper, we investigate the interaction between the vertices of neighboring regions. It is shown how the magnetic structure of the vertices of the domains changes as they approach each other with the help of an increasing constant magnetic field applied along the axis of easy magnetization. The distance was measured between the vertices of the domains. The schemes of distribution of the magnetization vectors between interacting vertices are shown. These schemes are made from experimental images of the magnetic structure. The distances between domain vertices and domain walls were compared on the basis of experimental data. The film thickness is 50 nm; the structure is Ni0.83-Fe0.17. The films were obtained by the method proposed by us. From the experimental results it follows that the interaction of the domain walls is observed at a distance of 20 microns and the interaction of the domain vertices is manifested at a distance of 100 μm.


1993 ◽  
Vol 313 ◽  
Author(s):  
Kamakhya P Ghatak ◽  
S. N. Biswas

ABSTRACTIn this paper we have studied the dia and paramagnetic susceptibilities of the holes in ultrathin films of dilute magnetic materials in the presence of a quantizing magnetic field and compared the same with that of the bulk specimens under magnetic quantization for the purpose of relative comparison. It is found, taking Hg1−xMnxTe and Cd1−xMnxSe as examples, that both the susceptibilities increase with decreasing film thickness and increasing surface concentration in oscillatory Manners. The numerical values of the susceptibilities in ultrathin films of dilute magnetic materials are greater than that of the bulk and the theoretical analysis is in agreement with the experimental data as reported elsewhere.


2004 ◽  
Vol 126 (3) ◽  
pp. 468-470 ◽  
Author(s):  
Sayavur I. Bakhtiyarov ◽  
Mihai Dupac ◽  
Ruel A. Overfelt ◽  
Sorin G. Teodorescu

In this paper, we propose a new relationship between the opposing mechanical torque and the electric conductivity of a rotating liquid specimen in a permanent external magnetic field of constant induction, which includes the effect of fluid flow. The proposed relationship was applied to describe the experimental data for a conductive specimens rotating in a permanent magnetic field.


Author(s):  
Kunio Shimada ◽  
Shigemitsu Shuchi ◽  
Shinichi Kamiyama

We made on numerical analysis of phase difference between pressure along the pipe axis and given oscillatory flow velocity in an straight pipe under a nonuniform steady magnetic field. In the analysis, a few cases under the assumption of numerical condition were conducted on: the first is taking into account the least compressibility of the fluid with using the obtained experimental data of the bulk modulus, the second taking into account the nonuniform distribution of mass concentration of particles, and the thrid taking into account the aggregation with the number of aggregated particles proposing as a prorate spheroid. By considering the three effects of the least compressibility and the nonuniform distribution of mass concentration, the aggregation as a prorate spheroid, the phase difference varies quantitatively at the lowest Womersley number range. And then, the numerical results were compared with the experimental data.


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