scholarly journals The loss of energy in metal plates of finite thickness, due to eddy currents produced by alternating magnetic fields

1926 ◽  
Vol 111 (759) ◽  
pp. 604-614 ◽  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Eddy Currents ◽  
Finite Thickness ◽  
Metal Plate ◽  
The Self ◽  
Alternating Magnetic Field ◽  
Metal Plates ◽  
Alternating Magnetic Fields

The induction of eddy currents in metal plates which are subjected to alternating magnetic fields has been discussed by Clerk-Maxwell, J. J. Thomson and many others. When an alternating magnetic field is produced normal to the surface of a metal plate, eddy currents are induced at the surface of the plate, which gradually penetrate its interior, the current dying away as it penetrates more deeply into the metal. The diffusion of the currents into the plate depends upon the self-induction and resistance of the paths along which they flow, and can be calculated by the same kind of formula as is used for determining the conduction of heat through a metal slab.

scholarly journals The Effect of Extremely Low Frequency Alternating Magnetic Field on the Behavior of Animals in the Presence of the Geomagnetic Field

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Natalia A. Belova ◽  
Daniel Acosta-Avalos
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Geomagnetic Field ◽  
Low Frequency ◽  
Alternating Magnetic Field ◽  
Magnetic Alignment ◽  
Resonance Model ◽  
Transduction Mechanisms ◽  
Alternating Magnetic Fields ◽  
The Magnetic Field

It is known that the geomagnetic field can influence animal migration and homing. The magnetic field detection by animals is known as magnetoreception and it is possible due to two different transduction mechanisms: the first one through magnetic nanoparticles able to respond to the geomagnetic field and the second one through chemical reactions influenced by magnetic fields. Another behavior is the magnetic alignment where animals align their bodies to the geomagnetic field. It has been observed that magnetic alignment of cattle can be disrupted near electric power lines around the world. Experimentally, it is known that alternating magnetic fields can influence living beings, but the exact mechanism is unknown. The parametric resonance model proposes a mechanism to explain that effect on living beings and establishes that, in the presence of a constant magnetic field, molecules associated with biochemical reactions inside cells can absorb resonantly alternating magnetic fields with specific frequencies. In the present paper, a review is made about animal magnetoreception and the effects of alternating magnetic fields in living beings. It is suggested how alternating magnetic fields can interfere in the magnetic alignment of animals and a general conclusion is obtained: alternating magnetic field pollution can affect the magnetic sensibility of animals.

scholarly journals New Magnetic Abrasive Finishing for Alumina Ceramic Plane Using Alternating Magnetic Fields

2019 ◽  
Vol 13 (6) ◽  
pp. 775-779
Author(s):  
Chaowen Dong ◽  
◽  
Yanhua Zou
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Diamond Particle ◽  
Alumina Ceramic ◽  
Alternating Magnetic Field ◽  
New Method ◽  
Magnetic Abrasive Finishing ◽  
Multi Stage ◽  
Abrasive Finishing ◽  
Alternating Magnetic Fields

In this paper, we propose a new plane magnetic abrasive finishing method, applicable to planes, that uses the alternating magnetic fields to solve problems such as the easy deformation and poor recovery of a magnetic brush in conventional magnetic abrasive finishing method. Compared with the magnetic brush used in conventional magnetic abrasive finishing, that in the new method can stably shape a workpiece under an alternating magnetic field. To determine the optimal finishing parameters, we focused on studying the effects of spindle rotational speed, size of diamond particle, and frequency of alternating magnetic field on the finishing surface. Then, according to the obtained optimal finishing parameters, multi-stage finishing experiments were performed with the new method. The results show that surface roughness can be improved from 230 nm Ra to 19 nm Ra in 60 min with the proposed method.

MAQNİT VƏ ELEKTROMAQNİT SAHƏLƏRİNİN FİZİOLOJİ VƏ TERAPEVTİK TƏSİR MEXANİZMLƏRİ

2019 ◽  
Vol 01 (01) ◽  
pp. 39-42
Author(s):  
Rahim Mahammad Rahimov ◽  
◽  
Khalil Firudin Khalilov ◽  
Keyword(s):  
Magnetic Field ◽  
Biological Activity ◽  
Magnetic Fields ◽  
Key Words ◽  
Alternating Magnetic Field ◽  
Electron Polarization

Key words: magnetic field, alternating magnetic field, sinusoidal and pulsating magnetic fields, electron polarization, biological activity

scholarly journals RANCANG BANGUN EXTERNAL ELECTROMAGNETIC RETARDERS SYSTEM PADA MOTOR 1 PHASA

2016 ◽  
Vol 18 (4) ◽  
pp. 1
Author(s):  
Bima Dicky Anugrah Dewantara ◽  
Saiful Manan
Keyword(s):  
Magnetic Field ◽  
New York ◽  
Eddy Currents ◽  
Focal Point ◽  
Metal Plate ◽  
Rotating Shaft ◽  
Braking System ◽  
Motor Current ◽  
Safety Systems ◽  
The Relationship

Bima Dicky Anugrah Dewantara, Saiful Manan, in this paper explain that Electromagnetic retarders are generally known as electromagnetic inhibitors or brakes, the braking system eliminates most braking mechanics, thereby reducing conventional braking systems. Safety requirements and safety systems are developed and become a focal point of an equipment. Electromagnetic brakes are a safety component with a control system that is easy to control. With this electromagnetic brake, it will reduce maintenance costs, because it only requires a factor of electricity to be able to move it. The braking system uses electromagnetic forces to slow down a movement, which is generally a shaft motion. A dish with non-ferromagnetic metal material is attached to a rotating shaft. The disk is flanked by the side of the stator in the form of an electromagnetic coil system that can generate a magnetic field from electricity. Electric current generates a magnetic field in the coil. And the metal plate that cuts the magnetic field will cause eddy currents on the disk itself. This eddy current will generate a magnetic field whose direction is opposite to the previous magnetic field, thus inhibiting the rotary motion of the shaft. In designing, experimenting and making an External Electromagnetic Retarders System Design on 1 Phase Motor, use the NE 555 IC as the control duty cycle. So that the relationship between braking current and braking time is inversely proportional if the higher the current, the shorter the time it takes for the rotor to stop. And the relationship between braking current and motor current is directly proportional, by increasing the braking current will increase the load on the motor causing the motor current to increase. Keywords: Electromagnetic Retarders, Electromagnetic Brakes, Eddy Flow EffectReferencesTipler, P. 2008. Physics for Scientist volume 2. New York : WH Freeman and Company..Ishaq, M. 2007. Fisika Dasar Elektisitas dan Magnetisme. Yogyakarta: Graha Ilmu.Millman, Halkias, M.Barmawi, dan M.O.Tjia. 1971. Integrated Electronics:Analog and Digital Circuits and Systems. Jakarta : Erlangga.Ramdhani, Mohamad. 2008. Rangkaian Listrik. Jakarta : Erlangga.Bishop, Owen. 2004. Dasar-Dasar Elektronika. Jakarta : Erlangga.Halliday, David. Robert Resnick. 1978. Fisika Jilid II Edisi Ketiga. Jakarta : Erlangga

scholarly journals Release of proteins and enzymes from vesicular compartments by alternating magnetic fields

2015 ◽  
Vol 17 (24) ◽  
pp. 15579-15588 ◽  
Author(s):  
Andrew Booth ◽  
Inmaculada C. Pintre ◽  
Yue Lin ◽  
Julie E. Gough ◽  
Simon J. Webb
Keyword(s):  
Magnetic Fields ◽  
Magnetite Nanoparticles ◽  
Self Assembly ◽  
The Self ◽  
Catalytically Active ◽  
Alternating Magnetic Fields

The self-assembly of avidin, biotinylated vesicles and biotinylated (3-aminopropyl)triethoxysilane-coated magnetite nanoparticles gave a nanomaterial able to magnetically release catalytically active enzymes from vesicular compartments.

scholarly journals The Role of Magnetic Fields in Star Forming Regions

1990 ◽  
Vol 140 ◽  
pp. 259-267
Author(s):  
L Mestel
Keyword(s):  
Magnetic Field ◽  
Star Formation ◽  
Magnetic Fields ◽  
The Self ◽  
Galactic Magnetic Field ◽  
Star Forming ◽  
Star Forming Regions

The flux from the galactic magnetic field alters radically the appropriate description of the equilibrium, collapse and fragmentation of the self-gravitating gas clouds that are the locale of star formation.

scholarly journals A Rapid Thermal Nanoimprint Apparatus through Induction Heating of Nickel Mold

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 334 ◽  
Author(s):  
Xinxin Fu ◽  
Qian Chen ◽  
Xinyu Chen ◽  
Liang Zhang ◽  
Aibin Yang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Cooling Rate ◽  
Induction Heating ◽  
Nanoimprint Lithography ◽  
High Speed ◽  
Eddy Currents ◽  
Magnetic Hysteresis ◽  
Alternating Magnetic Field ◽  
Polymer Materials ◽  
Heating And Cooling

Thermal nanoimprint lithography is playing a vital role in fabricating micro/nanostructures on polymer materials by the advantages of low cost, high throughput, and high resolution. However, a typical thermal nanoimprint process usually takes tens of minutes due to the relatively low heating and cooling rate in the thermal imprint cycle. In this study, we developed an induction heating apparatus for the thermal imprint with a mold made of ferromagnetic material, nickel. By applying an external high-frequency alternating magnetic field, heat was generated by the eddy currents and magnetic hysteresis losses of the ferromagnetic nickel mold at high speed. Once the external alternating magnetic field was cut off, the system would cool down fast owe to the small thermal capacity of the nickel mold; thus, providing a high heating and cooling rate for the thermal nanoimprint process. In this paper, nanostructures were successfully replicated onto polymer sheets with the scale of 4-inch diameter within 5 min.

scholarly journals The energy loss of cosmic ray particles in metal plates

1937 ◽  
Vol 160 (901) ◽  
pp. 304-323 ◽  
Keyword(s):  
Magnetic Field ◽  
Energy Loss ◽  
Cosmic Ray ◽  
Metal Plate ◽  
Usual Method ◽  
Cloud Chamber ◽  
Zero Magnetic Field ◽  
Metal Plates ◽  
Curvature Measurements ◽  
The Difference

Measurements have been made of the energy loss of cosmic ray particles in metal plates, making use of a counter controlled cloud chamber in a magnetic field (Blackett 1936). A metal plate was placed across the centre of the chamber and the energy loss of a ray was deduced from the difference of the curvature of a track above and below the plate. Energy loss measurements by this method have been carried out by Anderson and Neddermeyer (1936) up to an energy of about 4 x 10 8 e-volts and recently by Crussard and Leprince-Ringuet (1937) up to an energy of 1·2 x 10 9 e-volts. The curvature measurements were made mainly by means of the optical null method recently described (Blackett 1937 a ) and this proved invaluable. It would have been hard to obtain so high an accuracy by the usual method of measuring coordinates. The curvature corrections to be applied to the measured curvatures were obtained by measurements on tracks in zero magnetic field (Blackett and Brode 1936). Two separate distortion curves were required, one for the top and one for the bottom of the chamber.

Comparison on Effect of Alternating and Stationary Magnetic Field on the Conductivity of NaCl Solutions

2011 ◽  
Vol 391-392 ◽  
pp. 1095-1099
Author(s):  
Lei Chen ◽  
Nan Li ◽  
Feng Chai ◽  
Shu Kang Cheng
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Moment ◽  
Experimental Results ◽  
Alternating Magnetic Field ◽  
Stationary Magnetic Field ◽  
Conductivity Change

NaCl solutions of different concentrations were exposed to alternating and stationary magnetic fields. The conductivity change of the NaCl solutions was measured. The change of the conductivity of the NaCl solutions under different amplitudes magnetic fields was studied. The differences of effect between stationary and alternating magnetic field on the conductivity of the NaCl solutions was compared. The principle of the effects of magnetic fields on conductivity of NaCl solutions was discussed. The process of magnetic moment deflexion effected by the alternating magnetic field was analyzed, which explained the experimental results that the conductivity was increased more larger when then the NaCl solutions were exposing to alternating magnetic field than stationary magnetic field.

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