scholarly journals Initial Results on Primary Field Cancellation of Magnetic Induction Spectroscopy Technique for Fetal Acidosis Detection using COMSOL Multiphysics

2021 ◽  
Vol 2071 (1) ◽  
pp. 012027
Author(s):  
S F Abdul Halim ◽  
M H Zakaria ◽  
Z Zakaria ◽  
A N Norali ◽  
A Mohd Noor ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Fetal Loss ◽  
Receiver Coil ◽  
Fetal Blood Sampling ◽  
Transmitter Coil ◽  
Invasive Method ◽  
Ph Level ◽  
Fetal Acidosis ◽  
Initial Results

Abstract Monitoring of fetal condition during labor could save hundred lives in a single year. During labor, fetus is at critical condition as acidosis may occur suddenly without any early symptoms. Invasive method such as Fetal Blood Sampling (FBS) has been used to detect the decline in pH level of fetus. However, fetal loss rate after FBS may range from 1.4% up to 25%. In this paper, magnetic field induction spectroscopy was implemented to determine fetal acidosis by using primary magnetic field cancellation technique. Magnetic Induction Spectroscopy (MIS) probe was design where transmitter coil (TX) is perpendicular to receiver coil (RX). The result shows that the secondary magnetic field produced have been successfully measured without any interruption from primary magnetic field. By using transmitter input 1A, it shows that voltage is inversely proportional to the blood pH due to the conductivity properties of blood.

scholarly journals Wireless Power Transfer Using Harvested Radio Frequency Energy with Magnetic Resonance Coupling to Charge Mobile Device Batteries

2021 ◽  
Vol 11 (16) ◽  
pp. 7707
Author(s):  
Neetu Ramsaroop ◽  
Oludayo O. Olugbara
Keyword(s):  
Magnetic Field ◽  
Magnetic Resonance ◽  
Radio Frequency ◽  
Mobile Device ◽  
Receiver Coil ◽  
Wireless Power ◽  
Magnetic Resonance Coupling ◽  
Transmitter Coil ◽  
Resonance Coupling ◽  
Rf Energy

This research paper presents the design of a wireless power transfer (WPT) circuit integrated with magnetic resonance coupling (MRC) and harvested radio frequency (RF) energy to wirelessly charge the battery of a mobile device. A capacitor (100 µF, 16 V) in the RF energy harvesting circuit stored the converted power, and the accumulated voltage stored in the capacitor was 9.46 V. The foundation of the proposed WPT prototype circuit included two coils (28 AWG)—a transmitter coil, and a receiver coil. The transmitter coil was energized by the alternating current (AC), which produced a magnetic field, which in turn induced a current in the receiver coil. The harvested RF energy (9.46 V) was converted into AC, which energized the transmitter coil and generated a magnetic field. The electronics in the receiver coil then converted the AC into direct current (DC), which became usable power to charge the battery of a mobile device. The experimental setup based on mathematical modeling and simulation displayed successful charging capabilities of MRC, with the alternate power source being the harvested RF energy. Mathematical formulae were applied to calculate the amount of power generated from the prototype circuit. LTSpice simulation software was applied to demonstrate the behavior of the different components in the circuit layout for effective WPT transfer.

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.

NUMERICAL SIMULATION OF MARANGONI MAGNETOHYDRODYNAMIC BIO-NANOFLUID CONVECTION FROM A NON-ISOTHERMAL SURFACE WITH MAGNETIC INDUCTION EFFECTS: A BIO-NANOMATERIAL MANUFACTURING TRANSPORT MODEL

2014 ◽  
Vol 14 (03) ◽  
pp. 1450039 ◽  
Author(s):  
O. ANWAR BÉG ◽  
M. FERDOWS ◽  
S. SHAMIMA ◽  
M. NAZRUL ISLAM
Keyword(s):  
Magnetic Field ◽  
Boundary Layer ◽  
Prandtl Number ◽  
Stream Function ◽  
Magnetic Induction ◽  
Body Force ◽  
Volume Fraction ◽  
Solid Volume Fraction ◽  
Convection Boundary Layer ◽  
Force Parameter

Laminar magnetohydrodynamic Marangoni-forced convection boundary layer flow of a water-based biopolymer nanofluid containing nanoparticles from a non-isothermal plate is studied. Magnetic induction effects are incorporated. A variety of nanoparticles are studied, specifically, silver, copper, aluminium oxide and titanium oxide. The Tiwari–Das model is utilized for simulating nanofluid effects. The normalized ordinary differential boundary layer equations (mass, magnetic field continuity, momentum, induced magnetic field and energy conservation) are solved subject to appropriate boundary conditions using Maple shooting quadrature. The influence of Prandtl number (Pr), magnetohydrodynamic body force parameter (β), reciprocal of magnetic Prandtl number (α) and nanofluid solid volume fraction (φ) on velocity, temperature and magnetic stream function distributions is investigated in the presence of strong Marangoni effects (ξ i.e., Marangoni parameter is set as unity). Magnetic stream function is accentuated with body force parameter. The flow is considerably decelerated as is magnetic stream function gradient, with increasing nanofluid solid volume fraction, whereas temperatures are significantly enhanced. Interesting features in the flow regime are explored. The study finds applications in the fabrication of complex biomedical nanofluids, biopolymers, etc.

Computational Design for Digitally Fabricated 3D Inductive Power Transfer Coils

2022 ◽  
pp. 1-28
Author(s):  
Jun Xu ◽  
Eugeni L. Doubrovski ◽  
Jo Geraedts ◽  
Yu Song
Keyword(s):  
Design Method ◽  
Computational Design ◽  
Future Research ◽  
Receiver Coil ◽  
Power Transfer ◽  
Coil Design ◽  
Optimal Position ◽  
Inductive Power Transfer ◽  
Transmitter Coil ◽  
Inductive Power

Abstract The geometric shapes and the relative position of coils influence the performance of a three-dimensional (3D) inductive power transfer system. In this paper, we propose a coil design method for specifying the positions and the shapes of a pair of coils to transmit the desired power in 3D. Given region of interests (ROIs) for designing the transmitter and the receiver coils on two surfaces, the transmitter coil is generated around the center of its ROI first. The center of the receiver coil is estimated as a random seed position in the corresponding 3D surface. At this position, we use the heatmap method with electromagnetic constraints to iteratively extend the coil until the desired power can be transferred via the set of coils. In each step, the shape of the extension, i.e. a new turn of the receiver coil, is found as a spiral curve based on the convex hulls of adjacent turns in the 2D projection plane along their normal direction. Then, the optimal position of the receiver coil is found by maximizing the efficiency of the system. In the next step, the position and the shape of the transmitter coil are optimized based on the fixed receiver coil using the same method. This zig-zag optimization process iterates until an optimum is reached. Simulations and experiments with digitally fabricated prototypes were conducted and the effectiveness of the proposed 3D coil design method was verified. Possible future research directions are highlighted well.

scholarly journals XVII.—The Superposition of Mechanical Vibrations (Electric Oscillations) upon Magnetisation, and Conversely, in Iron, Steel, and Nickel

1907 ◽  
Vol 45 (2) ◽  
pp. 491-517
Author(s):  
James Russell
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Simple Experiment ◽  
Earth’S Magnetic Field ◽  
Mechanical Vibrations ◽  
Subsequent Work ◽  
Magnetic Condition ◽  
Earth's Magnetic Field ◽  
Mechanical Disturbances

That mechanical vibrations affect magnetisation has long been known. The simple experiment of hammering an iron rod (Gilbert) in the earth's magnetic field needs only to be mentionedAbout twenty years ago Ewing published investigations upon the effects of vibrations on magnetism. These have been summarised in his subsequent work, Magnetic Induction in Iron and other Metals. He states (§ 84, 3rd ed.) that the “influence of vibrations and mechanical disturbances generally” “may be succinctly described by saying that vibration lessens those differences of magnetic condition to which hysteresis gives rise. Thus, if we tap a piece of iron during the application and removal of a magnetising force, we find at each stage of the application that tapping increases the susceptibility, and at each stage of the removal it reduces the retentiveness.”

scholarly journals The fluxgate magnetometer of the Low Orbit Pearl Satellites (LOPS): overview of in-flight performance and initial results

2021 ◽  
Vol 10 (2) ◽  
pp. 227-243
Author(s):  
Ye Zhu ◽  
Aimin Du ◽  
Hao Luo ◽  
Donghai Qiao ◽  
Ying Zhang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Current System ◽  
Field Measurements ◽  
Stray Field ◽  
Fluxgate Magnetometer ◽  
General Description ◽  
Flight Performance ◽  
Spatial Coverage ◽  
Magnetic Field Measurements ◽  
Initial Results

Abstract. The Low Orbit Pearl Satellite series consists of six constellations, with each constellation consisting of three identical microsatellites that line up just like a string of pearls. The first constellation of three satellites were launched on 29 September 2017, with an inclination of ∼ 35.5∘ and ∼ 600 km altitude. Each satellite is equipped with three identical fluxgate magnetometers that measure the in situ magnetic field and its low-frequency fluctuations in the Earth's low-altitude orbit. The triple sensor configuration enables separation of stray field effects generated by the spacecraft from the ambient magnetic field (e.g., Zhang et al., 2006). This paper gives a general description of the magnetometer including the instrument design, calibration before launch, in-flight calibration, in-flight performance, and initial results. Unprecedented spatial coverage resolution of the magnetic field measurements allow for the investigation of the dynamic processes and electric currents of the ionosphere and magnetosphere, especially for the ring current and equatorial electrojet during both quiet geomagnetic conditions and storms. Magnetic field measurements from LOPS could be important for studying the method to separate their contributions of the Magnetosphere-Ionosphere (M-I) current system.

scholarly journals On the crustal bias of repeat stations in Romania

2013 ◽  
Vol 55 (6) ◽  
Author(s):  
Venera Dobrica ◽  
Crisan Demetrescu ◽  
Razvan Greculeasa ◽  
Anca Isac
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Curie Temperature ◽  
Magnetic Induction ◽  
Electromagnetic Induction ◽  
Reference Station ◽  
Lateral Variation ◽  
Field Campaigns ◽  
Induction Model ◽  
Geomagnetic Measurements

<p>A magnetic induction model has been applied to recordings obtained in 2010 during the field campaigns for geomagnetic measurements at the 26 repeat stations of the Romanian secular variation network. The model is based on the observation that a variable external magnetic field induces a response of the Earth's interior not only by electromagnetic induction, but also by magnetic induction in the magnetic rocks above the Curie temperature. The model computes coefficients of a linear relationship between recorded values of a certain geomagnetic element (X, Y, Z, or F) at the repeat station and recorded X, Y, Z values at a reference station (in this case, SUA observatory). Coefficients depend on magnetic permeabilities of rocks beneath the station and stand as a proxy for the anomaly bias characterizing the site. Maps of the lateral variation of this type of information were obtained and discussed.</p>

scholarly journals Design of 2MHz OOK transmitter/receiver for inductive power and data transmission for biomedical implant

2019 ◽  
Vol 9 (4) ◽  
pp. 2779 ◽  
Author(s):  
Abdelali El Boutahiri ◽  
Mounir Ouremchi ◽  
Ahmed Rahali ◽  
Mustapha El Alaoui ◽  
Fouad Farah ◽  
...  
Keyword(s):  
Data Transmission ◽  
Supply Voltage ◽  
Receiver Coil ◽  
Cmos Process ◽  
Power Transfer ◽  
Biomedical Implant ◽  
Transmitter Coil ◽  
Implant System ◽  
Inductive Power ◽  
Class E

<p>In this work a 2 MHz on-off keying (OOK) transmitter/receiver for inductive power and data transmission for biomedical implant system is presented. Inductive link, driven by a Class E power amplifier (PA) is the most PA used to transfer data and power to the internal part of biomedical implant system. Proposed transmitter consists of a digital control oscillator (DCO) and a class E PA which uses OOK modulation to transfer both data and power to a biomedical implant. In proposing OOK transmitter when the transmitter sends binary value “0” the DCO and PA are turned off. With this architecture and 2 MHz carrier wave we have implemented a wireless data and power transfer link which can transmit data with data rate 1Mbps and bit error rate (BER) of 10-5. The efficiency of power transfer is 42% with a 12.7 uH transmitter coil and a 2.4 uH receiver coil and the power delivered to the load is about 104.7 mW. Proposed transmitter is designed for output power 4.1V. OOK receiver consists of an OOK demodulator, powered by rectified and regulated 5V p-p RF signal across the receiver coil. The supply voltage of proposed voltage regulator is 5 V with 9mV/V line regulation of. All circuits proposed in this paper were designed and simulated using Cadence in 0.18 um CMOS process.</p>

Study of Pulsed Magnetic Field Generator for Magnetoacoustic Tomography Technology with Magnetic Induction

2011 ◽  
Vol 383-390 ◽  
pp. 805-810
Author(s):  
Yan Hong Li ◽  
Guo Qiang Liu ◽  
Shi Qiang Li ◽  
Hui Xia
Keyword(s):  
Magnetic Field ◽  
Magnetic Induction ◽  
Operation Mode ◽  
Pulsed Magnetic Field ◽  
Good Prospect ◽  
Inductive Load ◽  
Impedance Tomography ◽  
Charging System ◽  
Narrow Width ◽  
Magnetic Field Generator

On the basis of contrasting the research of home and abroad, this paper studies array magnetoacoustic tomography with magnetic induction as well logging new method. The paper introduces the design of the pulsed magnetic field for magnetoacoustic tomography with magnetic induction, analyses operational principle and parameters of charging system, introduces the operation mode of the discharging system in detail, the constitution of key parts circular plate coil, and realizes narrow width, high peak and repeat pulsed current with inductive load finally, and we obtained the distribution of the magnetic field. Magnetoacoustic tomography with magnetic induction combines the technology of Electrical Impedance Tomography and ultrasonic imaging, it can provide an impedance image with good accuracy and high spatial resolution, the method has a good prospect of application and extension in detection of resource, medical imaging and other fields.

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