Permanent magnet assembly producing a strong tilted homogeneous magnetic field: towards magic angle field spinning NMR and MRI

2010 ◽  
Vol 48 (12) ◽  
pp. 903-908 ◽  
Author(s):  
Dimitris Sakellariou ◽  
Cédric Hugon ◽  
Angelo Guiga ◽  
Guy Aubert ◽  
Sandrine Cazaux ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Homogeneous Magnetic Field ◽  
Magic Angle

Simulation and Optimization of a Permanent Magnet for Small-Sized MRI by Genetic Algorithm

2013 ◽  
Vol 341-342 ◽  
pp. 577-580
Author(s):  
Yi Yuan Cheng ◽  
Ling Xia ◽  
Wei He
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Homogeneous Magnetic Field ◽  
Main Magnetic Field ◽  
Resonance Imaging ◽  
Simulation And Optimization ◽  
Field Uniformity ◽  
Main Magnet ◽  
Magnetic Resonance Imaging Mri ◽  
The Magnetic Field

The main magnet produces the main magnetic field in the imaging area as one of the important parts of the magnetic resonance imaging (MRI) system. In a permanent MRI magnet, the widespread end effect causes a non-uniform magnetic field distribution and affects the imaging quality. In this paper, an H-type permanent magnet for small-sized MRI applications was designed; in particular, we added an optimized shimming ring outside the pole piece to improve the magnetic field uniformity. Genetic algorithms are used to solve the complex and nonlinear calculation of the magnetic field. The simulation results show that the magnet optimized by the proposed method generates a homogeneous magnetic field that can be easily implemented in practice.

Formation of a homogeneous magnetic field in spectrometer dipole magnet using permanent magnet

1992 ◽  
Vol 28 (1) ◽  
pp. 568-570 ◽  
Author(s):  
V.D. Borisov ◽  
V.S. Kashikhin ◽  
E.A. Lamzin ◽  
S.P. Potekhin ◽  
Y.P. Severgin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Homogeneous Magnetic Field ◽  
Dipole Magnet

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

A novel analytical calculation of magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping

2020 ◽  
pp. 1-15
Author(s):  
Jianqi Li ◽  
Yu Zhou ◽  
Jianying Li
Keyword(s):  
Magnetic Field ◽  
Conformal Mapping ◽  
Permanent Magnet ◽  
Flux Density ◽  
Analytical Method ◽  
Electromotive Force ◽  
Analytical Calculation ◽  
Air Gap ◽  
Permanent Magnet Machines ◽  
Peak Value

This paper presented a novel analytical method for calculating magnetic field in the slotted air gap of spoke-type permanent-magnet machines using conformal mapping. Firstly, flux density without slots and complex relative air-gap permeance of slotted air gap are derived from conformal transformation separately. Secondly, they are combined in order to obtain normalized flux density taking account into the slots effect. The finite element (FE) results confirmed the validity of the analytical method for predicting magnetic field and back electromotive force (BEMF) in the slotted air gap of spoke-type permanent-magnet machines. In comparison with FE result, the analytical solution yields higher peak value of cogging torque.

Study of Reactance Evaluation Methods in Saturated Magnetic Field for Permanent Magnet Synchronous Motor

2006 ◽  
Vol 126 (12) ◽  
pp. 1722-1729 ◽  
Author(s):  
Akeshi Takahashi ◽  
Haruo Koharagi ◽  
Satoshi Kikuchi ◽  
Kazumasa Ide ◽  
Kazuo Shima
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Permanent Magnet Synchronous Motor ◽  
Synchronous Motor ◽  
Evaluation Methods

Notizen: Effect of Magnetic Field on Ascorbic Acid Oxidase Activity, I

1986 ◽  
Vol 41 (3) ◽  
pp. 355-358 ◽  
Author(s):  
V. S. Ghole ◽  
P. S. Damle ◽  
W. H.-P. Thiemann
Keyword(s):  
Magnetic Field ◽  
Ascorbic Acid ◽  
Homogeneous Magnetic Field ◽  
Acid Oxidase ◽  
High Substrate Concentration ◽  
Ascorbic Acid Oxidase ◽  
Rate Of Reaction ◽  
Substrate Concentrations ◽  
Burk Plot

A homogeneous magnetic field of 1.1 T strength exhibits a significant influence on the activity of the enzyme ascorbic acid oxidase in vitro. A Lineweaver-Burk plot of the reaction shows the typical pattern of a mixed-type inhibition, i.e. a larger rate of reaction at low substrate concentrations and a smaller rate of reaction at high substrate concentration than that of the control without magnetic field applied.

scholarly journals Design of a New 1D Halbach Magnet Array with Good Sinusoidal Magnetic Field by Analyzing the Curved Surface

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2522
Author(s):  
Guangdou Liu ◽  
Shiqin Hou ◽  
Xingping Xu ◽  
Wensheng Xiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Permanent Magnet ◽  
Flux Density ◽  
Permanent Magnets ◽  
Air Gap ◽  
Curved Surface ◽  
Magnetic Flux Density ◽  
Sinusoidal Magnetic Field ◽  
The Magnetic Field

In the linear and planar motors, the 1D Halbach magnet array is extensively used. The sinusoidal property of the magnetic field deteriorates by analyzing the magnetic field at a small air gap. Therefore, a new 1D Halbach magnet array is proposed, in which the permanent magnet with a curved surface is applied. Based on the superposition of principle and Fourier series, the magnetic flux density distribution is derived. The optimized curved surface is obtained and fitted by a polynomial. The sinusoidal magnetic field is verified by comparing it with the magnetic flux density of the finite element model. Through the analysis of different dimensions of the permanent magnet array, the optimization result has good applicability. The force ripple can be significantly reduced by the new magnet array. The effect on the mass and air gap is investigated compared with a conventional magnet array with rectangular permanent magnets. In conclusion, the new magnet array design has the scalability to be extended to various sizes of motor and is especially suitable for small air gap applications.

Sign in / Sign up

Export Citation Format

Share Document