scholarly journals Sobre el estado electro-tónico y su interpretación: el potencial vectorial -On the Electro-Tonic State and its Interpretation: The Vector Potential

2015 ◽  
Vol 2 (22) ◽  
pp. 45
Author(s):  
Mauricio Rozo-Clavijo ◽  
Sandra Ávila-Torres ◽  
Angélica Walteros-Rodríguez

Se presenta un análisis acerca de las perspectivas que surgieron sobre el potencial vectorial a partir de los escritos originales de Faraday y Maxwell. Se muestran las primeras ideas sobre los experimentos y las explicaciones que Faraday desarrolló en torno a la inducción magnética, y la influencia que tuvo su concepto de estado electro-tónico en la primera explicación que formuló Maxwell, quien lo definió como el estado mediante el cual se ejecutan las acciones magnéticas a través de líneas de fuerza. Señala que ese concepto es la base para explicar el fenómeno de la inducción magnética en términos no newtonianos y lo formaliza mediante la variación temporal de la circulación del potencial vectorial a lo largo de una trayectoria cerrada. Este tipo de análisis muestra la manera en que estos pensadores representan el fenómeno, la cual no se evidencia en la literatura, sino que se muestra como una formalización alrededor del campo magnético.On the Electro-Tonic State and its Interpretation: The Vector PotentialAn analysis is presented on the emerging perspectives about the vector potential from Faraday and Maxwell’s original writings. This paper presents the initial observations about the experiments and explanations developed by Faraday on Magnetic Induction and the influence that his concept of Electrotonic State had on Maxwell’s first explanation. He defined it as the state by which magnetic actions are executed through lines of force. He pointed out that this concept is critical to explain the phenomenon of Magnetic Induction in non-Newtonian terms. Therefore, he formalized it by the circulation of vector potential throughout a closed trajectory. This kind of analysis shows how these researchers represented the phenomenon which is not evident in literature. It’s presented as a formalization around magnetic field instead.Sobre o estado electro-tônica e sua interpretação: o potencial vetorMostra-se uma análise ao redor das miradas que surgiram sobre o potencial vectorial a partir dos escritos originais de Faraday e Maxwell, com o fim de evidenciar as primárias ideias que estes pensadores desenvolvem sobre o fenómeno de indução. Realiza-se uma análise sobre os experimentos e explicações que foram desenvolvidos em torno da indução magnética por Faraday, em onde se evidência uma forte influência deste sobre Maxwell em torno da explicação da indução, já que este se apoia na ideia de estado electro-tónico proposta por Faraday como uma primeira explicação ao fenômeno. Ao estado electro-tónico, Maxwell caracteriza- o como o estado do médio pelo que se executam as acções magnéticas através de linhas de força. Assinala que o estado electro-tónico é a base para a explicação do fenómeno em termos não newtonianos e o formaliza por médio da variação temporária da circulação do potencial vectorial ao longo de uma trajectória fechada. Leste tipo de análise permite evidenciar a maneira como estes pensadores fazem uma representação do fenómeno, a qual não é evidenciada na literatura senão que pelo contrário se mostra como uma formalización ao redor do campo magnético.

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé

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.


2020 ◽  
pp. 3-7
Author(s):  
Vladlen Ya. Shifrin ◽  
Denis I. Belyakov ◽  
Alexander E. Shilov ◽  
Denis D. Kosenko

The results of works aimed at increasing the level of uniformity of measurements of the magnetic induction of a constant field – the basic value in the field of magnetic measurements. A set of equipment for reproducing a unit of magnetic induction of a constant field in the range of 1–25 mT was created and described. The inclusion of this complex in the State primary standard of units of magnetic induction, magnetic flux, magnetic moment and magnetic induction gradient GET 12-2011 will ensure the reproduction and direct transmission of the unit of permanent magnetic induction in the ranges of not only weak (10–3–1 mT), but medium (1–25 mT) and strong (0.025–1 T) magnetic fields. A quantum cesium magnetometer based on the resolved structure of cesium atoms was created to transmit the unit of magnetic induction to the region of medium fields. The procedure for calculating the frequency conversion coefficients to magnetic induction of the created quantum cesium magnetometer is described. The uncertainty budget for reproducing a unit of magnetic induction of a constant field using the created complex is estimated.


2021 ◽  
pp. 019145372110330
Author(s):  
Sandro Chignola

This article addresses the modern concept of sovereignty as a multivocal and conflictual semantic field, arguing for the necessity to trace its genealogy based on the structural tensions that haunt its logical framework – as well as its representations – rather than on a linear historiographic reconstruction. In particular, the scrutiny I propose aims to examine a series of exchanges that have been characterizing this concept since the beginning: the global and the European, the maritime and the territorial, the colony and the state, the imperial and the proprietary. The problematic balance between ‘imperium’ and ‘dominium’ is indeed assumed here as the turning point of the rise of a sovereign power that appears to be originally rooted in the very production and governance of the global space, thus giving up all possible Eurocentric narratives of modernity. To illustrate my argument, I focus on the frontispieces to three of Thomas Hobbes’s most important books, that is, his translation of Thucydides’ Peloponnesian Wars, De Cive and Leviathan. A thorough analysis of these images enables us to understand how these lines of force traverse the very heart of modern European political concepts, along with the mirroring effects that constantly bounce their normative construction of subjectivity back and forth from the periphery to the centre and, ultimately, from the market to the state.


2014 ◽  
Vol 14 (03) ◽  
pp. 1450039 ◽  
Author(s):  
O. ANWAR BÉG ◽  
M. FERDOWS ◽  
S. SHAMIMA ◽  
M. NAZRUL ISLAM

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.


Author(s):  
A.V. Volkov ◽  
◽  
A.A. Khadartsev ◽  
L.V. Kashintseva ◽  
O.A. Sedova ◽  
...  

The paper presents the results of the analysis of scientific publications in order to identify heliogeophysical interactions and their impact on the state of biospheric processes. It is demonstrated that small disturbances in the biological environment lead to global process-es with little predictable consequences that radically change politics, economics and public health. These processes pose a serious threat to national and economic security. The studies have shown that the Earth's ionosphere is a complex dynamic system, the state of which is de-termined not only by the parameters of the atmosphere itself, but also by variations in helium and geomagnetic factors. Investigation of interrelated processes in the lower and upper lay-ers of the atmosphere is one of the priority geophysical and meteorological tasks. Key words: solar activity, heliogeophysical interactions; the Earth's magnetic field; interplanetary field; annual variations; cosmic rays.


Author(s):  
K. Mendelssohn ◽  
J. D. Babbitt ◽  
Frederick Alexander Lindemann

Until a year ago it was generally accepted that if a body is made supraconducting while in a magnetic field the lines of magnetic force were "frozen in," i. e ., whatever lines of force passed through the body at the time when it became supraconducting remained there afterwards, unaffected by any change in the external field, so long as the body was supraconducting. Meissner and Ochsenfeld, however, showed that this supposition was not true. They measured field strengths in the immediate neighbourhood of cylinders which had been cooled to supraconductivity in an external magnetic field, and found that the field of force was then of the same nature as that to be expected in the neighbourhood of perfectly diamagnetic bodies. Thus it appeared that when a body becomes supraconducting in a magnetic field the lines of force are all pressed out of the body, and the induction inside the body falls to zero. At the same time, however, these authors report on another experiment, the result of which appears to us not entirely in accordance with the assumption that the induction in the whole body became zero. They measured the field strengths inside and outside a hollow cylinder, after it had become supraconducting in a field perpendicular to its axis, and found again that the field strength outside was as if the cylinder were almost perfectly diamagnetic, but the field inside was appreciably the same as if the cylinder were non-supraconducting. We therefore made a number of experiments, hoping to find out more exactly the nature of the phenomenon.


1907 ◽  
Vol 45 (2) ◽  
pp. 491-517
Author(s):  
James Russell

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.”


2013 ◽  
Vol 55 (6) ◽  
Author(s):  
Venera Dobrica ◽  
Crisan Demetrescu ◽  
Razvan Greculeasa ◽  
Anca Isac

<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>


2011 ◽  
Vol 383-390 ◽  
pp. 805-810
Author(s):  
Yan Hong Li ◽  
Guo Qiang Liu ◽  
Shi Qiang Li ◽  
Hui Xia

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.


Author(s):  
Volodymyr Kozyrskyi ◽  
Mykola Zablodskiy ◽  
Vitaliy Savchenko ◽  
Oleksandr Sinyavsky ◽  
Rauf Yuldashev ◽  
...  

The reclamation of new areas and distant lands with limited energy and material resources demands using resource- and energy-saving technologies. One of such technologies can be magnetic treatment of irrigating water and artificial manure solutions, and presowing treatment of seeds of agricultural crops in magnetic field. The authors found that magnetic field accelerates the velocity of chemical reactions, enhances salts and fertilizers solvability, and increases oxygen concentration in a solution. Magnetic field improves membrane cells permeability which accelerates molecules and ions diffusion through it. This process improves the ability of a seed to absorb water and increases the concentration of oxygen in a cell. Presowing treatment of seeds increases their ability of germination by 26–50%, sprouting by 20–30%. The best regime of water solutions and seeds of agricultural crops treatment in magnetic field is when magnetic induction is 0.065 Tl and the velocity of a solution is 0.4 m/s.


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