scholarly journals Accuracy of the Magnetic Field Gradient Waveform Monitor Technique and Consequent Accuracy of Pre-Equalized Gradient Waveform

2016 ◽  
Vol 46B (2) ◽  
pp. 67-80 ◽  
Author(s):  
Frédéric G. Goora ◽  
Bruce J. Balcom
2018 ◽  
Author(s):  
Mahendran Subramanian ◽  
Arkadiusz Miaskowski ◽  
Stuart Iain Jenkins ◽  
Jenson Lim ◽  
Jon Dobson

AbstractThe manipulation of magnetic nanoparticles (MNPs) using an external magnetic field, has been demonstrated to be useful in various biomedical applications. Some techniques have evolved utilizing this non-invasive external stimulus but the scientific community widely adopts few, and there is an excellent potential for more novel methods. The primary focus of this study is on understanding the manipulation of MNPs by a time-varying static magnetic field and how this can be used, at different frequencies and displacement, to manipulate cellular function. Here we explore, using numerical modeling, the physical mechanism which underlies this kind of manipulation, and we discuss potential improvements which would enhance such manipulation with its use in biomedical applications, i.e., increasing the MNP response by improving the field parameters. From our observations and other related studies, we infer that such manipulation depends mostly on the magnetic field gradient, the magnetic susceptibility and size of the MNPs, the magnet array oscillating frequency, the viscosity of the medium surrounding MNPs, and the distance between the magnetic field source and the MNPs. Additionally, we demonstrate cytotoxicity in neuroblastoma (SH-SY5Y) and hepatocellular carcinoma (HepG2) cells in vitro. This was induced by incubation with MNPs, followed by exposure to a magnetic field gradient, physically oscillating at various frequencies and displacement amplitudes. Even though this technique reliably produces MNP endocytosis and/or cytotoxicity, a better biophysical understanding is required to develop the mechanism used for this precision manipulation of MNPs, in vitro.


2010 ◽  
Vol 82 (6) ◽  
Author(s):  
Min-Kang Zhou ◽  
Zhong-Kun Hu ◽  
Xiao-Chun Duan ◽  
Bu-Liang Sun ◽  
Jin-Bo Zhao ◽  
...  

2019 ◽  
Vol 878 (2) ◽  
pp. 124 ◽  
Author(s):  
Virgilio Quattrociocchi ◽  
Giuseppe Consolini ◽  
Maria Federica Marcucci ◽  
Massimo Materassi

2017 ◽  
Vol 83 (2) ◽  
Author(s):  
Yongjie Ding ◽  
Peng Li ◽  
Xu Zhang ◽  
Liqiu Wei ◽  
Hezhi Sun ◽  
...  

The effect of the magnetic field gradient in the discharge channel of a Hall thruster on the ionization of the neutral gas and power deposition on the wall is studied through adopting the 2D-3V particle-in-cell (PIC) and Monte Carlo collisions (MCC) model. The research shows that by gradually increasing the magnetic field gradient while keeping the maximum magnetic intensity at the channel exit and the anode position unchanged, the ionization region moves towards the channel exit and then a second ionization region appears near the anode region. Meanwhile, power deposition on the walls decreases initially and then increases. To avoid power deposition on the walls produced by electrons and ions which are ionized in the second ionization region, the anode position is moved towards the channel exit as the magnetic field gradient is increased; when the anode position remains at the zero magnetic field position, power deposition on the walls decreases, which can effectively reduce the temperature and thermal load of the discharge channel.


2003 ◽  
Vol 163 (1) ◽  
pp. 1-7 ◽  
Author(s):  
David J. Goodyear ◽  
Maurice Shea ◽  
Steven D. Beyea ◽  
Nadim J. Shah ◽  
Bruce J. Balcom

Author(s):  
Hatice Bilgili ◽  
Teymuraz Abbasov ◽  
Yusuf Baran

Separation processes are widely used in chemical and biotechnical processes. Especially biomagnetic separation is an important issue among effective separation processes to separate the magnetic micron and submicron particles. It is necessary to establish and determine a high magnetic field or field gradient in the separation cell. However, it is not easy to determine the magnetic field gradient in the working region for different separation in practice. The reason for these difficulties is that the magnetic cells used in biochemical separation have different geometries and there are no simple and useful systems to easily measure these magnetic fields. Two main objectives are aimed in this study. First, a simple measuring device design can measure gradient magnetic fields with high precision of about 0,01mm and, secondly, obtain simple empirical expressions for the magnetic field. A magnetometer with Hall probes that works with the 3D printer principle was designed and tested to measure the magnetic field. Magnetic field changes were measured according to the surface coordinates on the measurement platform or measuring cell. Numerous experimental measurements of gradient magnetic fields generated by permanent magnets have been taken. The results obtained from the studies and results from the proposed empirical models were compared.


2020 ◽  
Vol 87 (8) ◽  
Author(s):  
Ali Shademani ◽  
Mu Chiao

Abstract Magnetic elastomers (MEs) respond to an applied magnetic field through magnetomechanical coupling, where the mechanical properties of the MEs change with magnetic field strength. These phenomena have been mostly studied under homogenous magnetic fields due to the simplicity. In this work, the effects of the magnetic field gradient on the mechanical properties and the response of the MEs was examined. MEs are made by embedding carbonyl iron microparticles (CI) into a polydimethylsiloxane (PDMS) matrix, which is later rendered porous. The influence of the CI concentration was investigated by manipulating four different samples with CI/PDMS weight ratios of 0.2, 0.6, 1.0, and 1.4. An analytical method was proposed to further understand the interactions of the magnetic field gradient and the material’s response. The proposed theory was later verified with experimental results from compression tests in the presence of different magnetic fields. The proposed theoretical framework and experimental methods can be used to improve the design of MEs in the future.


1997 ◽  
Vol 36 (Part 1, No. 2) ◽  
pp. 905-909 ◽  
Author(s):  
Yoshiteru Kondo ◽  
Mitsuyo Saito ◽  
Masafumi Yamashita ◽  
Toshiharu Tako ◽  
Atsuo Morinaga

2016 ◽  
Vol 09 (01) ◽  
pp. 1650003 ◽  
Author(s):  
Pengfei Gao ◽  
Tie Liu ◽  
Meng Dong ◽  
Yi Yuan ◽  
Kai Wang ◽  
...  

We investigated how high magnetic field gradients affected the magnetostrictive performance of Tb[Formula: see text]Dy[Formula: see text]Fe[Formula: see text] during solidification. At high applied magnetic field gradients, the magnetostriction exhibited a gradient distribution throughout the alloy. Increasing the magnetic field gradient also increased the magnetostriction gradient. We attributed the graded magnetostrictive performance to the gradient distribution of (Tb, Dy)Fe2 phase in the alloy and its orientation.


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