Tuning mass transport in magnetic nanoparticle-filled viscoelastic hydrogels using low-frequency rotating magnetic fields

Soft Matter ◽  
2017 ◽  
Vol 13 (36) ◽  
pp. 6259-6269 ◽  
Author(s):  
Shahab Boroun ◽  
Faïçal Larachi
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Mass Transport ◽  
Magnetic Nanoparticle ◽  
Low Frequency ◽  
Rotating Magnetic Field ◽  
Rotating Magnetic Fields ◽  
Rotational Movement

Rotational movement of MNPs in ferrogels in an external rotating magnetic field for tuning mass transport.

Behaviors of Bio-Functionalized Magnetic Nanoparticle Clusters in a Rotating Magnetic Field

2012 ◽  
Author(s):  
Chin-Yih Hong ◽  
Ji-Ching Lai ◽  
Chia-Chung Tang
Keyword(s):  
Magnetic Field ◽  
Aqueous Solution ◽  
Magnetic Nanoparticles ◽  
Magnetic Fields ◽  
Magnetic Nanoparticle ◽  
Critical Diameter ◽  
Rotating Magnetic Field ◽  
Magnetic Clusters ◽  
Rotating Magnetic Fields ◽  
Nanoparticle Clusters

Manipulation of magnetic nanoparticles has many applications in several fields and the behaviors of magnetic nanoparticles subjected to rotating or alternating magnetic fields attracted more attention from biomedical applications. In an aqueous solution containing bio-functionalized magnetic nanoparticles, due to the interaction between biomolecules, these nanoparticles agglomerate and form clusters with various sizes and shapes. In this study, the behaviors of magnetic nanoparticle clusters in an aqueous solution under rotating magnetic fields were investigated. Due to the interaction between the rotating magnetic field and the net magnetic dipole moment, the clusters were subjected to forced vibration. Two motion modes of clusters were observed as the magnetic field rotated. These two modes are rotation and oscillation. The diameters of the magnetic clusters with rotational or oscillational motions were measured. A critical diameter range of magnetic cluster was defined and the range is between 10.21 μm and 6.17 μm that could be used to distinguish rotation and oscillation of clusters.

Frequency-dependent conversion of the torque of a rotating magnetic field on a ferrofluid confined in a spherical cavity

Soft Matter ◽  
2019 ◽  
Vol 15 (44) ◽  
pp. 9018-9030
Author(s):  
Klaus D. Usadel ◽  
Anastasiya Storozhenko ◽  
Igor Arefyev ◽  
Hajnalka Nádasi ◽  
Torsten Trittel ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
Magnetic Fields ◽  
Spherical Cavity ◽  
Rotating Magnetic Field ◽  
Rotating Magnetic Fields ◽  
Frequency Dependent

The dynamics of magnetic nanoparticles in rotating magnetic fields is studied both experimentally and theoretically.

Control of the Macrosegregations during Solidification of a Binary Alloy by Means of a AC Magnetic Field

2006 ◽  
Vol 508 ◽  
pp. 163-168 ◽  
Author(s):  
Xiao Dong Wang ◽  
A. Ciobanas ◽  
Florin Baltaretu ◽  
Anne Marie Bianchi ◽  
Yves Fautrelle
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Mushy Zone ◽  
Binary Alloy ◽  
Solidification Front ◽  
Laminar Flows ◽  
Rotating Magnetic Field ◽  
Moderate Intensity ◽  
Mushy Region ◽  
Rotating Magnetic Fields

A numerical model aimed at simulating the segregations during the columnar solidification of a binary alloy is used to investigate the effects of a forced convection. Our objective is to study how the segregation characteristics in the mushy zone are influenced by laminar flows driven both by buoyancy and by AC fields of moderate intensity. Various types of magnetic fields have been tested, namely travelling, rotating magnetic field and slowly modulated electromagnetic forces. The calculations have been achieved on two types of alloys, namely tin-lead and aluminiumsilicon. It is shown that the flow configuration changes the segregation pattern. The change comes from the coupling between the liquid flow and the top of the mushy zone via the pressure distribution along the solidification front. The pressure difference along the front drives a mush flow, which transports the solute in the mushy region. Another interesting type of travelling magnetic field has been tested. It consists of a slowly modulated travelling magnetic field. It is shown that in a certain range of values of the modulation period, the channels are almost suppressed. The normal macrosegregation remains, but the averaged segregation in the mushy zone is weaker than in the natural convection case. The optimal period depends on the electromagnetic force strength as well as the cooling rate. The latter phenomenon cannot occur in the case of rotating magnetic fields, since in that configuration the sign of the pressure gradient along the solidification front remains unchanged. Recent solidification experiments with electromagnetic stirring confirm the predicted macrosegregation patterns.

Semiconductor Crystal Growth by the Vertical Bridgman Process With Transverse Rotating Magnetic Fields

2006 ◽  
Vol 129 (2) ◽  
pp. 241-243 ◽  
Author(s):  
X. Wang ◽  
N. Ma
Keyword(s):  
Magnetic Field ◽  
Crystal Growth ◽  
Magnetic Fields ◽  
Applied Magnetic Field ◽  
Rotating Magnetic Field ◽  
Semiconductor Crystal ◽  
Rotating Magnetic Fields ◽  
Electrically Conducting ◽  
Vertical Bridgman ◽  
Bridgman Process

During the vertical Bridgman process, a single semiconductor crystal is grown by the solidification of an initially molten semiconductor contained in an ampoule. The motion of the electrically conducting molten semiconductor can be controlled with an externally applied magnetic field. This paper treats the flow of a molten semiconductor and the dopant transport during the vertical Bridgman process with a periodic transverse or rotating magnetic field. The frequency of the externally applied magnetic field is sufficiently low that this field penetrates throughout the molten semiconductor. Dopant distributions in the crystal are presented.

scholarly journals Power and Momentum Relations in Rotating Magnetic Field Current Drive

1984 ◽  
Vol 37 (5) ◽  
pp. 509 ◽  
Author(s):  
WN Hugrass
Keyword(s):  
Magnetic Field ◽  
Angular Momentum ◽  
Magnetic Fields ◽  
Phase Velocity ◽  
Current Drive ◽  
Rotating Magnetic Field ◽  
Plasma Current ◽  
Rotating Magnetic Fields ◽  
Frequency Source ◽  
Rotating Field

The use of rotating magnetic fields (RMF) to drive steady currents in plasmas involves a transfer of energy and angular momentum from the radio frequency source feeding the rotating field coils to the plasma. The. power-torque relationships in RMF systems are discussed and the analogy between RMF current drive and the polyphase induction motor is explained. The general relationship between the energy and angular momentum transfer is utilized to calculate the efficiency of the RMF plasma current drive. It is found that relatively high efficiencies can be achieved in RMF current drive because of the low phase velocity and small slip between the rotating field and the electron fluid.

The orbits of electrons and ions in the fields of the rotamak

1987 ◽  
Vol 37 (1) ◽  
pp. 1-13 ◽  
Author(s):  
W. N. Hugrass ◽  
M. Turley
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Charged Particles ◽  
The Self ◽  
Rotating Magnetic Field ◽  
Plasma Equilibrium ◽  
Rotating Magnetic Fields ◽  
Cylindrical Plasma ◽  
Electrons And Ions ◽  
Self Consistent

The motion of electrons and ions in the self-consistent fields of a compact toroidal equilibrium maintained by means of a rotating magnetic field is studied. It is found that the particles are confined although the lines of the instantaneous magnetic field are open. The results are compared with those obtained in an earlier study of the motion of charged particles in the self-consistent fields appropriate to cylindrical plasma equilibrium maintained by means of rotating magnetic fields.

Particle Actuation by Rotating Magnetic Fields in Microchannels: A Numerical Study

Soft Matter ◽  
2021 ◽  
Author(s):  
Seokgyun Ham ◽  
Wen-Zhen Fang ◽  
Rui Qiao
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Particles ◽  
Numerical Study ◽  
Rotating Magnetic Field ◽  
Rotating Magnetic Fields ◽  
Translation Motion

Magnetic particles confined in microchannels can be actuated to perform translation motion using a rotating magnetic field, but their actuation in such a situation is not yet well understood. Here,...

scholarly journals Modulation of Cellular Response to Different Parameters of the Rotating Magnetic Field (RMF)—An In Vitro Wound Healing Study

2021 ◽  
Vol 22 (11) ◽  
pp. 5785
Author(s):  
Magdalena Jedrzejczak-Silicka ◽  
Marian Kordas ◽  
Maciej Konopacki ◽  
Rafał Rakoczy
Keyword(s):  
Magnetic Field ◽  
Wound Healing ◽  
Magnetic Fields ◽  
Electric Fields ◽  
Metabolic Activity ◽  
Cellular Response ◽  
Healing Process ◽  
Low Frequency ◽  
Rotating Magnetic Field

Since the effect of MFs (magnetic fields) on various biological systems has been studied, different results have been obtained from an insignificant effect of weak MFs on the disruption of the circadian clock system. On the other hand, magnetic fields, electromagnetic fields, or electric fields are used in medicine. The presented study was conducted to determine whether a low-frequency RMF (rotating magnetic field) with different field parameters could evoke the cellular response in vitro and is possible to modulate the cellular response. The cellular metabolic activity, ROS and Ca2+ concentration levels, wound healing assay, and gene expression analyses were conducted to evaluate the effect of RMF. It was shown that different values of magnetic induction (B) and frequency (f) of RMF evoke a different response of cells, e.g., increase in the general metabolic activity may be associated with the increasing of ROS levels. The lower intracellular Ca2+ concentration (for 50 Hz) evoked the inability of cells to wound closure. It can be stated that the subtle balance in the ROS level is crucial in the wound for the effective healing process, and it is possible to modulate the cellular response to the RMF in the context of an in vitro wound healing.

scholarly journals The hardening of metals by rotating magnetic fields

1931 ◽  
Vol 130 (814) ◽  
pp. 514-523 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Work Hardening ◽  
Rotating Magnetic Fields ◽  
Hardening Process ◽  
Hard Steel ◽  
Steel Balls ◽  
Hardened Condition

In a previous paper by the author experiments were described in which the hardness of various metals was increased by rotating them in a magnetic field. It had been observed that metals in a work-hardened condition, and in particular hard steel which had been super-hardened by the “Cloudburst” process of bombardment with steel balls, exhibit a propensity to become still harder by a process of ageing, the spontaneous increase of hardness commencing with the termination of the work-hardening process, and contiuning during a period of several hours or days.

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