scholarly journals On interactions of static magnetic fields

2019 ◽  
Vol 70 (3) ◽  
pp. 253-255
Author(s):  
Ömer Zor
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Interaction Energy ◽  
Magnetic Charge ◽  
Dirac Monopole ◽  
Static Magnetic Fields ◽  
The Universe

Abstract We investigated the interaction energy of a Gilbertian magnetic charge with each of the “point” magnetic field sources. Finally we extrapolated a Dirac string can only be defined if there is at most one Dirac monopole in the medium. If there is only one Dirac monopole/string in the universe, the probability of detecting it is essential zero, such that Dirac’s monopole would remain just a “theorist’s particle”.

FINITE ENERGY ONE-HALF MONOPOLE SOLUTIONS

2012 ◽  
Vol 27 (40) ◽  
pp. 1250233 ◽  
Author(s):  
ROSY TEH ◽  
BAN-LOONG NG ◽  
KHAI-MING WONG
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Magnetic Flux ◽  
Topological Charge ◽  
Magnetic Monopole ◽  
Magnetic Charge ◽  
Finite Energy ◽  
Spatial Infinity ◽  
Yang Mills ◽  
The Magnetic Field

We present finite energy SU(2) Yang–Mills–Higgs particles of one-half topological charge. The magnetic fields of these solutions at spatial infinity correspond to the magnetic field of a positive one-half magnetic monopole at the origin and a semi-infinite Dirac string on one-half of the z-axis carrying a magnetic flux of [Formula: see text] going into the origin. Hence the net magnetic charge is zero. The gauge potentials are singular along one-half of the z-axis, elsewhere they are regular.

scholarly journals Novel static magnetic field effects on green chemistry biosynthesis of silver nanoparticles in Saccharomyces cerevisiae

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ameni Kthiri ◽  
Selma Hamimed ◽  
Abdelhak Othmani ◽  
Ahmed Landoulsi ◽  
Siobhan O’Sullivan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Saccharomyces Cerevisiae ◽  
Silver Nanoparticles ◽  
Magnetic Fields ◽  
Green Chemistry ◽  
Static Magnetic Field ◽  
Culture Medium ◽  
Average Diameter ◽  
Magnetic Field Effects ◽  
Static Magnetic Fields

AbstractThe bacteriocidal properties of silver nanoparticles (AgNPs) depend on their average diameter (toxicity increases with decreasing diameter). In the present work, we describe novel green chemistry biosynthesis of AgNPs from AgNO3 added to cell-free culture medium of baker’s yeast, Saccharomyces cerevisiae, yielding nanoparticles in the range 11–25 nm. However, when yeast was grown in a moderate static magnetic field, AgNPs obtained from the resulting cell-free culture medium, were significantly smaller (2–12 nm) than those obtained without magnetic field. These latter nanoparticles were highly crystalline, stable and near-uniform shape. Furthermore, the antibacterial activity of AgNPs obtained from static magnetic fields were greater than those from control cultures. Static magnetic fields show a promising ability to generate biocidal nanoparticles via this novel green chemistry approach.

Static magnetic fields in vacuum

2018 ◽  
Author(s):  
J. Pierrus
Keyword(s):  
Magnetic Field ◽  
Problem Solving ◽  
Magnetic Fields ◽  
Vector Potential ◽  
Scalar Potential ◽  
Multipole Expansion ◽  
Magnetic Vector Potential ◽  
Magnetic Dipoles ◽  
Static Magnetic Fields ◽  
The Magnetic Field

Wherever possible, an attempt has been made to structure this chapter along similar lines to Chapter 2 (its electrostatic counterpart). Maxwell’s magnetostatic equations are derived from Ampere’s experimental law of force. These results, along with the Biot–Savart law, are then used to determine the magnetic field B arising from various stationary current distributions. The magnetic vector potential A emerges naturally during our discussion, and it features prominently in questions throughout the remainder of this book. Also mentioned is the magnetic scalar potential. Although of lesser theoretical significance than the vector potential, the magnetic scalar potential can sometimes be an effective problem-solving device. Some examples of this are provided. This chapter concludes by making a multipole expansion of A and introducing the magnetic multipole moments of a bounded distribution of stationary currents. Several applications involving magnetic dipoles and magnetic quadrupoles are given.

scholarly journals Magnetism in the Early Universe

2018 ◽  
Vol 14 (A30) ◽  
pp. 295-298
Author(s):  
Tina Kahniashvili ◽  
Axel Brandenburg ◽  
Arthur Kosowsky ◽  
Sayan Mandal ◽  
Alberto Roper Pol
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Gravitational Waves ◽  
Early Universe ◽  
Large Scale ◽  
Direct Detection ◽  
Correlation Lengths ◽  
Cosmological Scenario ◽  
Expansion Of The Universe ◽  
The Universe

AbstractBlazar observations point toward the possible presence of magnetic fields over intergalactic scales of the order of up to ∼1 Mpc, with strengths of at least ∼10−16 G. Understanding the origin of these large-scale magnetic fields is a challenge for modern astrophysics. Here we discuss the cosmological scenario, focussing on the following questions: (i) How and when was this magnetic field generated? (ii) How does it evolve during the expansion of the universe? (iii) Are the amplitude and statistical properties of this field such that they can explain the strengths and correlation lengths of observed magnetic fields? We also discuss the possibility of observing primordial turbulence through direct detection of stochastic gravitational waves in the mHz range accessible to LISA.

scholarly journals Mouse Magnetic-field Nystagmus in Strong Static Magnetic Fields Is Dependent on the Presence of Nox3

2018 ◽  
Vol 39 (10) ◽  
pp. e1150-e1159 ◽  
Author(s):  
Bryan K. Ward ◽  
Yoon H. Lee ◽  
Dale C. Roberts ◽  
Ethan Naylor ◽  
Americo A. Migliaccio ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Static Magnetic Fields

scholarly journals PLANETARY MAGNETIC FIELD AND GRAVITY IN THE SOLAR SYSTEM

2017 ◽  
Vol 5 (9) ◽  
pp. 145-151
Author(s):  
Samir A Hamouda ◽  
Eman A. Alsslam Alfadeel ◽  
Mohamed Belhasan Mohamed
Keyword(s):  
Magnetic Field ◽  
Solar System ◽  
Magnetic Fields ◽  
Difficult Problem ◽  
Planetary Scale ◽  
Scale Models ◽  
Planetary Magnetic Fields ◽  
Solar System Bodies ◽  
Planetary Magnetic Field ◽  
The Universe

Gravity plays a major role in the planetary formation and the development of the solar system. Gravity attraction is the essence of a power that holds and governs the universe; it makes the planets in the solar system revolve around the sun and the moons around their planets. Magnetic fields are also an important phenomenon in the solar system and beyond. Their causes are complex and have a variety of effects on their surroundings; they have become a critical tool for the exploration of solar system bodies. However, the study of the mechanisms of planets formation in the solar system is a difficult problem made more so by the inability to construct planetary-scale models for laboratory study. However, understanding the nature of the matter comprising the Solar System is crucial for understanding the mechanism that generates planetary magnetic fields and planetary gravity. In this study, a brief history about the development of planetary gravity is presented. Some data about the physical properties of planets in the solar system are presented and discussed. However, much work is still needed before the planetary gravity and planetary magnetic field processes are fully understood and full advantage be taken of the implications of both phenomena  observations.

scholarly journals Magnetic Field Evolution in Neutron Star Crusts: Beyond the Hall Effect

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 130
Author(s):  
Konstantinos N. Gourgouliatos ◽  
Davide De Grandis ◽  
Andrei Igoshev
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Neutron Stars ◽  
Hall Effect ◽  
Thermal Emission ◽  
Ohmic Dissipation ◽  
Field Evolution ◽  
The Universe ◽  
The Magnetic Field ◽  
Maxwell Stresses

Neutron stars host the strongest magnetic fields that we know of in the Universe. Their magnetic fields are the main means of generating their radiation, either magnetospheric or through the crust. Moreover, the evolution of the magnetic field has been intimately related to explosive events of magnetars, which host strong magnetic fields, and their persistent thermal emission. The evolution of the magnetic field in the crusts of neutron stars has been described within the framework of the Hall effect and Ohmic dissipation. Yet, this description is limited by the fact that the Maxwell stresses exerted on the crusts of strongly magnetised neutron stars may lead to failure and temperature variations. In the former case, a failed crust does not completely fulfil the necessary conditions for the Hall effect. In the latter, the variations of temperature are strongly related to the magnetic field evolution. Finally, sharp gradients of the star’s temperature may activate battery terms and alter the magnetic field structure, especially in weakly magnetised neutron stars. In this review, we discuss the recent progress made on these effects. We argue that these phenomena are likely to provide novel insight into our understanding of neutron stars and their observable properties.

scholarly journals A search for strong magnetic fields in massive and very massive stars in the Magellanic Clouds

2020 ◽  
Vol 635 ◽  
pp. A163
Author(s):  
S. Bagnulo ◽  
G. A. Wade ◽  
Y. Nazé ◽  
J. H. Grunhut ◽  
M. E. Shultz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Longitudinal Magnetic Field ◽  
Massive Stars ◽  
Magellanic Clouds ◽  
Dipolar Field ◽  
Strong Magnetic Fields ◽  
Ob Stars ◽  
Stellar Magnetic Fields ◽  
The Universe

Despite their rarity, massive stars dominate the ecology of galaxies via their strong, radiatively-driven winds throughout their lives and as supernovae in their deaths. However, their evolution and subsequent impact on their environment can be significantly affected by the presence of a magnetic field. While recent studies indicate that about 7% of OB stars in the Milky Way host strong, stable, organised (fossil) magnetic fields at their surfaces, little is known about the fields of very massive stars, nor the magnetic properties of stars outside our Galaxy. We aim to continue searching for strong magnetic fields in a diverse set of massive and very massive stars (VMS) in the Large and Small Magellanic Clouds (LMC/SMC), and we evaluate the overall capability of FORS2 to usefully search for and detect stellar magnetic fields in extra-galactic environments. We have obtained FORS2 spectropolarimetry of a sample of 41 stars, which principally consist of spectral types B, O, Of/WN, WNh, and classical WR stars in the LMC and SMC. Four of our targets are Of?p stars; one of them was just recently discovered. Each spectrum was analysed to infer the longitudinal magnetic field. No magnetic fields were formally detected in our study, although Bayesian statistical considerations suggest that the Of?p star SMC 159-2 is magnetic with a dipolar field of the order of 2.4–4.4 kG. In addition, our first constraints of magnetic fields in VMS provide interesting insights into the formation of the most massive stars in the Universe.

scholarly journals Effects of the electron spin on the nonlinear generation of quasi-static magnetic fields in a plasma

2010 ◽  
Vol 76 (6) ◽  
pp. 865-873 ◽  
Author(s):  
M. STEFAN ◽  
G. BRODIN ◽  
F. HAAS ◽  
M. MARKLUND
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Electron Spin ◽  
High Frequency ◽  
Significant Contribution ◽  
Magnetic Field Generation ◽  
Temperature Plasma ◽  
Static Magnetic Fields ◽  
Nonlinear Generation ◽  
The Magnetic Field

AbstractThrough an extended kinetic model, we study the nonlinear generation of quasi-static magnetic fields by high-frequency fields in a plasma, taking into account the effects of the electron spin. It is found that although the largest part of the nonlinear current in a moderate density, moderate temperature plasma is due to the classical terms, the spin may still give a significant contribution to the magnetic field generation mechanism. Applications of our results are discussed.

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