magnetic component
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2022 ◽  
Vol 924 (2) ◽  
pp. 75
Author(s):  
Youhei Masada ◽  
Tomoya Takiwaki ◽  
Kei Kotake

Abstract To study properties of magnetohydrodynamic (MHD) convection and resultant dynamo activities in proto-neutron stars (PNSs), we construct a “PNS in a box” simulation model and solve the compressible MHD equation coupled with a nuclear equation of state (EOS) and simplified leptonic transport. As a demonstration, we apply it to two types of PNS model with different internal structures: a fully convective model and a spherical-shell convection model. By varying the spin rate of the models, the rotational dependence of convection and the dynamo that operate inside the PNS is investigated. We find that, as a consequence of turbulent transport by rotating stratified convection, large-scale structures of flow and thermodynamic fields are developed in all models. Depending on the spin rate and the depth of the convection zone, various profiles of the large-scale structures are obtained, which can be physically understood as steady-state solutions to the “mean-field” equation of motion. Additionally to those hydrodynamic structures, a large-scale magnetic component of  ( 10 15 ) G is also spontaneously organized in disordered tangled magnetic fields in all models. The higher the spin rate, the stronger the large-scale magnetic component grows. Intriguingly, as an overall trend, the fully convective models have a stronger large-scale magnetic component than that in the spherical-shell convection models. The deeper the convection zone extends, the larger the size of the convective eddies becomes. As a result, rotationally constrained convection seems to be more easily achieved in the fully convective model, resulting in a higher efficiency of the large-scale dynamo there. To gain a better understanding of the origin of the diversity of a neutron star’s magnetic field, we need to study the PNS dynamo in a wider parameter range.


2021 ◽  
Vol 243 (1) ◽  
Author(s):  
M. A. Castillo Corzo ◽  
L. E. Borja-Castro ◽  
L. De Los Santos Valladares ◽  
J. C. González ◽  
J. Medina Medina ◽  
...  

AbstractWe present the magnetic, structural and 57Fe Mossbauer characterization of soils collected from an ancient mercury contaminated city named Huancavelica in Peru. The characterization results indicate that silicates and carbonates are the main mineralogical constituents in the samples. In addition, 57Fe Mössbauer spectra at room temperature reveal, the presence of two components: a magnetic component related to magnetic Fe-oxides (magnetite, hematite, goethite) and a high non-magnetic component related to Fe+3 in high spin configuration and tetrahedral coordination in silicates. The magnetization measurements present screening of paramagnetic, ferromagnetic and antiferromagnetic signals, typical from soils containing different silicates and iron minerals. Remarkably the Verwey and Morin transitions corresponding to magnetite and hematite, respectively, are screened by the paramagnetic signal corresponding to the major silicate components in the samples. Overall, the soils are mainly composed of crystalline and amorphous silicates, calcites and iron bearing which are typical from Andean soils.


2021 ◽  
Vol 72 (6) ◽  
pp. 366-373
Author(s):  
Steffen Kühn

Abstract The magnetic component of the Lorentz force acts exclusively perpendicular to the direction of motion of a test charge, whereas the electric component does not depend on the velocity of the charge. This article provides experimental indication that, in addition to these two forces, there is a third electromagnetic force that (i) is proportional to the velocity of the test charge and (ii) acts parallel to the direction of motion rather than perpendicular. This force cannot be explained by the Maxwell equations and the Lorentz force, since it is mathematically incompatible with this framework. However, this force is compatible with Weber electrodynamics and Ampère’s original force law, as this older form of electrodynamics not only predicts the existence of such a force but also makes it possible to accurately calculate the strength of this force.


2021 ◽  
Author(s):  
Yongpeng Chen ◽  
Jianguo Zhang ◽  
Ying Li ◽  
Jiawei Zhang ◽  
Huichao Zhang ◽  
...  

Abstract The development of new electromagnetic interference materials has attracted much attention in the information warfare. Herein, a novel KPA@Fe3O4 composite particle was synthesized via a microcrystalline co-precipitation method. X-ray diffractions, scanning electron microscopes and vibrating sample magnetometer measurements were used to characterize the products. The results indicated that the surface of the potassium picrate (KPA) crystals was covered by magnetic Fe3O4 nanoparticles, and composite particles exhibited excellent magnetic properties. Furthermore, the thermal behavior of the composite particles was investigated by differential scanning calorimetry, which showed that the composite particles inherited the energetic property of pure KPA crystals when the mass fraction of magnetic component was 50%, or 65%. As for the composite particles with 75% magnetic component, the thermal stability of was poor. In addition, the magnetic directional aggregation performance of composite particles was analyzed by dynamic simulation, which moved toward the magnetic source. For the composite particles with 50% magnetic component, the maximum concentration was about 63 times of the initial concentration, and the peak velocity was 0.63 m/s. With the mass fraction of magnetic component increasing to 65%, the concentration and velocity of the composite particles generally increased at the corresponding moment. As the mass fraction of magnetic component increased to 75%, the change of them was not obvious. Therefore, the composite particles with Fe3O4/KPA mass ratios of 65/35 had the best comprehensive properties. The excellent energetic and magnetic directional aggregation properties can allow the composites to be used in many potential applications in the information warfare.


2021 ◽  
Vol 68 (3) ◽  
pp. 1828-1840
Author(s):  
Hyun-Jun Choi ◽  
Bong-Gyo Seo ◽  
Myung-Hyo Ryu ◽  
Young-Pyo Cho ◽  
Jee-Hoon Jung

2021 ◽  
Author(s):  
Михаил Чеснаков

Аннотация Концепция, согласно которой все частицы находятся в непрерывной связи между собой, в статье дополнена концепцией развития структуры связанного состояния от простого к сложному. Показано, как в рамках модели последовательное усложнение структуры связанного состояния гипотетических мнимых частиц приводит к появлению материальных частиц с всевозможными формами взаимодействия и созданному частицами сложному пространству. При этом оказалось возможным объединить электрические, магнитные и силы гравитации. Масса не является формой потенциальной энергии, а является одним из двух компонентов импульса. По способу и месту образования существуют спиновая, оболочечная, релятивистская и зарядовая массы. Вектор электрической составляющей фотона на самом деле оказался вектором магнитной составляющей. Из модели также следует, что взаимодействие между частицами отвечает принципу квантовой нелокальности (информация о локализации частицы проходит со скоростью выше скорости света, следовательно, свойства частиц не определенны до взаимодействия), и, так называемая, «квантованная запутанность» есть следствие этого принципа. Abstract. The concept according to which all particles are in continuous communication with each other is supplemented in the article with the concept of the development of the structure of a bound state from simple to complex. It is shown how, within the framework of the model, the sequential complication of the structure of the bound state of hypothetical imaginary particles leads to the appearance of material particles with all possible forms of interaction and a complex space created by particles. In this case, it turned out to be possible to combine electric, magnetic and gravitational forces. Mass is not a form of potential energy, but one of two components of momentum. According to the method and place of formation, there are spin, shell, relativistic and charge masses. The vector of the electrical component of the photon actually turned out to be the vector of the magnetic component. It also follows from the model that the interaction between particles corresponds to the principle of quantum no locality (information about the localization of a particle passes at a speed higher than the speed of light, therefore, the properties of particles are not determined before the interaction), and the so-called "quantized entanglement" is a consequence of this principle.


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