Short-Duration High-Frequency Quasi-Sinusoidal Magnetic Field Generator

2005 ◽  
Vol 54 (6) ◽  
pp. 2481-2485
Author(s):  
G. Robles ◽  
R. Giannetti ◽  
J.D.M. Frias
Keyword(s):  
Magnetic Field ◽  
Short Duration ◽  
High Frequency ◽  
Sinusoidal Magnetic Field ◽  
Magnetic Field Generator

scholarly journals Configurable High-Frequency Alternating Magnetic Field Generator for Nanomedical Magnetic Hyperthermia Applications

IEEE Access ◽  
2021 ◽  
pp. 1-1
Author(s):  
Michael Zeinoun ◽  
Diego Serrano ◽  
Pablo Tezanos ◽  
Oscar Garcia ◽  
Miroslav Vasic ◽  
...  
Keyword(s):  
Magnetic Field ◽  
High Frequency ◽  
Magnetic Hyperthermia ◽  
Alternating Magnetic Field ◽  
Magnetic Field Generator

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.

scholarly journals Studies about the design of magnetic bionanocomposite

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Robert Müller ◽  
Janna Kuchinka ◽  
Thomas Heinze
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
Mössbauer Spectroscopy ◽  
Fatty Acid ◽  
Optical Microscopy ◽  
High Frequency ◽  
Mossbauer Spectroscopy ◽  
Fatty Acid Esters ◽  
Iron Oxide Particles ◽  
Mößbauer Spectroscopy

Abstract Magnetic nanocomposites are a class of smart materials that have attracted recent interest as drug delivery systems or as medical implants. A new approach toward the biocompatible nanocomposites suitable for remote melting is presented. It is shown that magnetite nanoparticles (MNPs) can be embedded into a matrix of biocompatible thermoplastic dextran esters. For that purpose, fatty acid esters of dextran with adjustable melting points in the range of 30–140 °C were synthesized. Esterification of the polysaccharide by activation of the acid as iminium chlorides guaranteed mild reaction conditions leading to high-quality products as confirmed by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy as well as by gel permeation chromatography (GPC). A method for the preparation of magnetically responsive bionanocomposites (BNCs) was developed consisting of combined dissolution/suspension of the dextran ester and hydrophobized MNPs in an organic solvent followed by homogenization with ultrasonication, casting of the solution, drying and melting of the composite for a defined shaping. This process leads to a uniform distribution of MNPs in BNC as revealed by scanning electron microscope (SEM). Samples of different geometries were exposed to high-frequency alternating magnetic field (AMF). It could be shown that defined remote melting of such biocompatible nanocomposites is possible for the first time. This may lead to a new class of magnetic remote-control systems, which are suitable for controlled release applications or self-healing materials. BNCs containing biocompatible dextran fatty acid ester melting close to human body temperature were prepared and loaded with Rhodamine B (RhB) or green fluorescent protein (GFP) as model drugs to evaluate their potential use as drug delivery system. The release of the model drugs from the magnetic BNC investigated under the influence of a high-frequency AMF (20 kA/m at 400 kHz) showed that on-demand release is realized by applying the external AMF. The BNC possessed a long-term stability (28 d) of the incorporated iron oxide particles after incubation in artificial body fluids. Temperature-dependent mobility investigations of MNP in the molten BNC were carried out by optical microscopy, magnetometry, alternating current (AC) susceptibility, and Mössbauer spectroscopy measurements. Optical microscopy shows a movement of agglomerates and texturing in the micrometer scale, whereas AC susceptometry and Mössbauer spectroscopy investigations reveal that the particles perform diffusive Brownian motion in the liquid polymer melt as separated particles rather than as large agglomerates. Furthermore, a texturing of MNP in the polymer matrix by a static magnetic field gradient was investigated. First results on the preparation of cross-linkable dextran esters are shown. Cross-linking after irradiation of the BNC prevents melting that can be used to influence texturing procedures.

A 60-Hz sinusoidal magnetic field induces apoptosis of prostate cancer cells through reactive oxygen species

2008 ◽  
Vol 84 (11) ◽  
pp. 945-955 ◽  
Author(s):  
Eui Kwan Koh ◽  
Byung-Kyu Ryu ◽  
Dong-Young Jeong ◽  
Iel-Soo Bang ◽  
Myung Hee Nam ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Prostate Cancer ◽  
Reactive Oxygen Species ◽  
Cancer Cells ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Prostate Cancer Cells ◽  
Sinusoidal Magnetic Field
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