scholarly journals Design parameters analysis and verification of angular vibration sensor based on magnetohydrodynamics

2021 ◽  
Vol 12 ◽  
pp. 2
Author(s):  
Kundong Wang ◽  
Youwei Ma ◽  
Jianming Wu ◽  
Qinghua Zhu ◽  
Yue Gu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Field Intensity ◽  
Vibration Sensor ◽  
Design Parameters ◽  
Design Requirement ◽  
Manufacturing Equipment ◽  
Satellite Platform ◽  
Angular Vibration ◽  
Parameters Analysis ◽  
Conducting Fluids

The angular vibration is concerned in many fields such as satellite platform, manufacturing equipment for micro-electromechanical systems. However, the angular vibration with a frequency more than 15 Hz is difficult to be measured by traditional gyroscopes. The angular vibration sensor based on Magnetohydrodynamics can meet the requirements of both wide bandwidth and higher precision. In order to optimize the structure, a response of conducting fluid in the static magnetic field to the angular vibration is modeled in this paper. Based on this model, the sensitivity of the design parameters of magnetic field intensity, conducting fluids' height and width are analyzed to get an optimized parameter for higher precision and bandwidth. A prototype was developed to verify the analysis and optimization. The experiment results showed that the model is accurate with 6.7% error in lower-cut-off frequency and 1.4% error in scale factor. It can meet the design requirement of 6–1000 Hz.

scholarly journals Effect of permanent magnetic field on scale inhibition property of circulating water

2017 ◽  
Vol 76 (8) ◽  
pp. 1981-1991 ◽  
Author(s):  
Lili Jiang ◽  
Xiayan Yao ◽  
Haitao Yu ◽  
Xingang Hou ◽  
Zongshu Zou ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Hydrogen Bonds ◽  
Flow Velocity ◽  
Magnetic Field Intensity ◽  
Water Molecules ◽  
Relative Variation ◽  
Initial Concentration ◽  
Circulating Water ◽  
Scale Inhibition ◽  
Inhibition Property

Effect of a permanent magnet field on the scale inhibition property of circulating water was investigated. Orthogonal experiments of L16(45) were performed and analyzed using the range analysis method. The operating parameters included magnetic field intensity, initial concentration of Ca2+ and Mg2+, magnetic treatment time, temperature, and flow velocity. Scale inhibition rate, hardness, relative variation in the proportion of free water molecules, electrical conductivity, and relative variation of molecular energy were chosen as the objectives. In addition, the morphology and the composition of CaCO3 and MgCO3 scale were studied by X-ray diffraction analysis. The optimal conditions were initial concentration of 900 mg/L, magnetic field intensity of 0.5 T, temperature of 303 K, time of 54 h and flow velocity of 0.17 m/s. The nuclear magnetic resonance results demonstrated that the number of hydrogen bonds increased between water molecules and hydrated ions. The magnetic field can promote the increase in the number of hydrogen bonds, which can inhibit the formation of calcium and magnesium carbonate precipitation. Moreover, the ratio of calcite, aragonite and vaterite will be changed at different magnetic field intensities, and the aragonite ratio will reach the peak at the optimum conditions.

Concurrent Vibration Suppression and Energy Harvesting Using Ferrofluids: An Experimental Investigation

2014 ◽  
Author(s):  
Saad F. Alazemi ◽  
Amin Bibo ◽  
Mohammed F. Daqaq
Keyword(s):  
Magnetic Field ◽  
Power Generation ◽  
Energy Harvesting ◽  
Vibration Suppression ◽  
Design Parameters ◽  
Structural Vibrations ◽  
Rectangular Container ◽  
Fluid Damper ◽  
Magnetized Ferrofluid ◽  
Experimental Response

This paper presents an experimental study which examines the design parameters affecting the performance characteristics of a Tuned Magnetic Fluid Damper (TMFD) device designed to concurrently mitigate structural vibrations and harvest vibratory energy. The device which is mounted on a vibrating structure, consists of a rectangular container carrying a magnetized ferrofluid and a pick-up coil wound around the container to enable energy harvesting. Experiments are performed to investigate the three-way interaction between the vibrations of the structure, the sloshing of the fluid, and the harvesting circuit dynamics. In particular, the tuning and optimization is examined for several design parameters including magnetic field spatial distribution and intensity, winding direction, winding location, winding density, and ferrofluid height inside the tank. The experimental response of the device is compared against the conventional TMFD at different excitation levels and frequencies. Results demonstrating the influence of the significant parameters on the relative performance are presented and discussed in terms of vibration suppression and power generation capabilities.

scholarly journals Magnetotaxis as a Means for Nanofabrication

2014 ◽  
Vol 23 (01n02) ◽  
pp. 1450008
Author(s):  
Isaac Macwan ◽  
Zihe Zhao ◽  
Omar Sobh ◽  
Jinnque Rho ◽  
Ausif Mahmood ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Field ◽  
Semiconductor Manufacturing ◽  
Magnetic Field Intensity ◽  
Magnetotactic Bacteria ◽  
Semiconductor Substrate ◽  
Field Lines ◽  
A Chain ◽  
Magnetospirillum Magneticum ◽  
The Magnetic Field

Magnetotactic bacteria (MTB), discovered in early 1970s contain single-domain crystals of magnetite ( Fe 3 O 4) called magnetosomes that tend to form a chain like structure from the proximal to the distal pole along the long axis of the cell. The ability of these bacteria to sense the magnetic field for displacement, also called magnetotaxis, arises from the magnetic dipole moment of this chain of magnetosomes. In aquatic habitats, these organisms sense the geomagnetic field and traverse the oxic-anoxic interface for optimal oxygen concentration along the field lines. Here we report an elegant use of MTB where magnetotaxis of Magnetospirillum magneticum (classified as AMB-1) could be utilized for controlled navigation over a semiconductor substrate for selective deposition. We examined 50mm long coils made out of 18AWG and 20AWG copper conductors having diameters of 5mm, 10mm and 20mm for magnetic field intensity and heat generation. Based on the COMSOL simulations and experimental data, it is recognized that a compound semiconductor manufacturing technology involving bacterial carriers and carbon-based materials such as graphene and carbon nanotubes would be a desirable choice in the future.

Stimuli-responsive Pickering emulsions: recent advances and potential applications

Soft Matter ◽  
2015 ◽  
Vol 11 (18) ◽  
pp. 3512-3529 ◽  
Author(s):  
Juntao Tang ◽  
Patrick James Quinlan ◽  
Kam Chiu Tam
Keyword(s):  
Magnetic Field ◽  
Ionic Strength ◽  
Light Intensity ◽  
Magnetic Field Intensity ◽  
Pickering Emulsion ◽  
Pickering Emulsions ◽  
Stimuli Responsive ◽  
Comprehensive Review ◽  
Potential Applications ◽  
Emulsion Systems

Pickering emulsions with stimuli-responsive properties have, in recent years, received a considerable amount of attention. This paper provides a concise and comprehensive review of Pickering emulsion systems that possess the ability to respond to an array of external triggers, including pH, temperature, CO2concentration, light intensity, ionic strength, and magnetic field intensity.

scholarly journals Multi-point ground-based ULF magnetic field observations in Europe during seismic active periods in 2004 and 2005

2008 ◽  
Vol 8 (3) ◽  
pp. 501-507 ◽  
Author(s):  
G. Prattes ◽  
K. Schwingenschuh ◽  
H. U. Eichelberger ◽  
W. Magnes ◽  
M. Boudjada ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Intensity ◽  
Seismic Activity ◽  
Magnetic Field Intensity ◽  
Field Measurements ◽  
Fluxgate Magnetometer ◽  
Vertical Magnetic Field ◽  
Earthquake Epicenter ◽  
Electromagnetic Noise ◽  
Horizontal Magnetic Field

Abstract. We present the results of ground-based Ultra Low Frequency (ULF) magnetic field measurements observed from June to August 2004 during the Bovec earthquake on 12 July 2004. Further we give information about the seismic activity in the local observatory region for an extended time span 2004 and 2005. ULF magnetic field data are provided by the South European Geomagnetic Array (SEGMA) where the experience and heritage from the CHInese MAGnetometer (CHIMAG) fluxgate magnetometer comes to application. The intensities of the horizontal H and vertical Z magnetic field and the polarization ratio R of the vertical and horizontal magnetic field intensity are analyzed taking into consideration three SEGMA observatories located at different close distances and directions from the earthquake epicenter. We observed a significant increase of high polarization ratios during strong seismic activity at the observatory nearest to the Bovec earthquake epicenter. Apart from indirect ionospheric effects electromagnetic noise could be emitted in the lithosphere due to tectonic effects in the earthquake focus region causing anomalies of the vertical magnetic field intensity. Assuming that the measured vertical magnetic field intensities are of lithospheric origin, we roughly estimate the amplitude of electromagnetic noise in the Earths crust considering an average electrical conductivity of <σ>=10−3 S/m and a certain distance of the observatory to the earthquake epicenter.

scholarly journals Kelvin-Helmholtz discontinuity in two superposed viscous conducting fluids in a horizontal magnetic field

2008 ◽  
Vol 12 (3) ◽  
pp. 103-110 ◽  
Author(s):  
Aiyub Khan ◽  
Neha Sharma ◽  
P.K. Bhatia
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Growth Rate ◽  
Unstable Mode ◽  
Two Dimensional ◽  
Horizontal Magnetic Field ◽  
Streaming Velocity ◽  
The Stability ◽  
Conducting Fluids ◽  
Streaming Motion

The Kelvin-Helmholtz discontinuity in two superposed viscous conducting fluids has been investigated in the taking account of effects of surface tension, when the whole system is immersed in a uniform horizontal magnetic field. The streaming motion is assumed to be two-dimensional. The stability analysis has been carried out for two highly viscous fluid of uniform densities. The dispersion relation has been derived and solved numerically. It is found that the effect of viscosity, porosity and surface tension have stabilizing influence on the growth rate of the unstable mode, while streaming velocity has a destabilizing influence on the system.

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