Magnetic Fields

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  • In this contribution several topics concerning magnetic fields and overhead medium voltage power lines are reviewed: simple formulation to assess the magnetic field (MF) level; characterization of magnetic fields generated by typical three-phase and one-phase primary distribution lines, with balanced and unbalanced current; and main mitigation techniques, analysed in relation with typical reduction level obtained. Additional data concerning cost and performance of different solutions are also provided....

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  • Physical Phenomena at High Magnetic Fields-IV (PPHMF-IV) was the fourth conference sponsored by the National High Magnetic Field Laboratory (NHMFL). The previous conferences were held in May, 1991, 1995, and 1998. These meetings brought together experts in scientific research areas where high magnetic fields could make an important impact. PPHMF-III devoted substantial time to reviewing the state of many fields in regard to the role of high magnetic fields, such as semiconductors, heavy fermions, superconductivity, and molecular conductors.

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  • Lecture Engineering electromagnetics - The steady magnetic field presents the following content: Biot – Savart law, Ampere’s circuital law, Curl, Stokes’ theorem, magnetic flux and magnetic flux density, magnetic potential, derivation of the steady – magnetic – field law.

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  • Micro-homogeneous solvent mixtures of propyl acetate (PA)/butyronitrile (BN) allow for a systematic variation of the static dielectric constants, s , in the range from 6.0 to 24.6. The mixtures of toluene (TO)/dimethylsulfoxide (DMSO) with varying the s values in the range from 4.3 to 15.5 are used as micro-heterogeneous binary solvents. In micro-heterogeneous environment, DMSO molecules get preferentially favoured in the solvation shell, forming micro-clusters surrounding the solute molecules.

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  • We investigate correlation and magnetic field effects on the mobility and resistivity of a quasi-two-dimensional electron gas in an InP/In1−xGaxAs/InP quantum well at arbitrary temperatures. We study the dependence of the mobility and resistivity on the carrier density, magnetic field, layer thickness and temperature for alloy disorder and impurity scattering using different approximations for the local-field correction.

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  • The Hall effect is studied theoretically in a doped semiconductor superlattice (DSSL) subjected to a crossed dc electric field and magnetic field in the presence of an intense electromagnetic wave (EMW). By using the quantum kinetic equation for electrons interacting with acoustic phonons at low temperature, we obtain expressions for the magnetoresistance as well as the Hall coefficient in dependence on the external fields and characteristic parameters of the DSSL. Analytical results are numerically evaluated for the GaAs:Si/GaAs:Be DSSL.

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  • In this paper, we have investigated the magnetic field effect on the lowest excitedstate binding energy of hydrogenic shallow-donor impurity in wurtzite (In,Ga)N/GaN parabolic transversal-section quantum-well wire (PQWW) using the finite-difference method within the quasione-dimensional effective potential model. The calculations are performed within the framework of the effective mass approximation.

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  • Effect of magnetic field on the electrodeposition of FeCo layers has been investigated with respect to the orientation of the magnetic field to surface electrode e.g magnetic field is parallel and perpendicular to electrode. Electrochemical behaviours, morphology, composition, structure and magnetic properties were investigated using cyclic voltammogram (CV), Scanning Electron Microscopy (SEM), Energy Dispersion Spectroscopy (EDS), X-Ray Diffractometer (XRD), Vibrating Sample Magnetometer (VSM).

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  • Due to the discriminate use of plant chemicals and their resultant negative impact on the environment, researchers are interested in monitoring plant behavior as modified by various nonchemical influences such as magnetic fields.

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  • The influence of magnetic field stimulation (MFS) on plants is a subject of intense research. The influence of MFS on plants varies depending on its intensity, time of exposure, and form of application.

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  • The aim of this paper is based on a subproblem technique with the magnetic vector potential formulation to compute magnetic fields, eddy currents and Joule power losses in electromagnetic screens that are extreamly difficult to perform by a finite element method.

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  •  Some history:  Magnetic effects from natural magnets have been known for a long time. Recorded observations from the Greeks more than 2500 years ago.  The word magnetism comes from the Greek word for a certain type of stone (lodestone) containing iron oxide found in Magnesia, a district in northern Greece.  Properties of lodestones: could exert forces on similar stones and could impart this property (magnetize) to a piece of iron it touched.

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  • Magnetism often has a slight overtone of being mysterious. This is probably caused by the surprisingly strong forces between magnets which everybody can experience with magnetic toys, magnet boards, or similar objects. A strange effect is the unique ability of magnetic fields to penetrate many substances without any attenuation. Though the physical basis of magnetism is well explored, the outsider usually does not know very much about the details and sometimes tends to overestimate the real possibilities provided by magnetism.

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  • Abstract The year 2008 marked the one hundredth anniversary of the observational discovery by George Ellery Hale of magnetic field in sunspots (Hale in Astrophys. J. 28:315–343, 1908). This observation, the first to suggest a direct link between the best-known variable features on the Sun and magnetism, started a line of research that has widened considerably over the last 100 years and is continuing today. Knowledge about all aspects of the Sun has increased in a remarkable way over the past few decades....

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  • The nation’s six synchrotron light sources, five neutron sources, and highfield magnet laboratory are uniquely valuable resources that contribute to the development of new products and processes, create jobs, enhance the skill level of the U.S. scientific community, and increase U.S. competitiveness. Because of the high cost of building and operating these facilities,1 only a limited number can be funded and they must be made widely available.

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  • This chapter presents the following content: Force on a moving charge, force on a differential current element, force between differential current elements, force and torque on a closed circuit, magnetization and permeability, magnetic boundary conditions, the magnetic circuit, potential energy of magnetic fields, inductance and mutual inductance.

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  • Photon - axion conversions in static electromagnetic fields of the size a × b × c are considered in detail by the Feynman diagram methods. The differential cross sections are presented and the numerical evaluations of the total cross section are given. Our result shows that the conversion cross-sections in the electric field are quite small, while in the strong magnetic field, the cross-sections are much enhanced, which can be measurable in current experiments.

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  • We have known the close connection between changing eletric fields and magnetic fields. They can create each other and form a system of electromagnetic fields.  Electromagnetic fields can propagate in the space (vacuum or material environment). We call them electromagnetic waves. They play a very important role in science and technology.

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  • NMR is an experiment in which the resonance frequencies of nuclear magnetic systems are investigated. NMR always employs some form of magnetic field (usually a strong externally applied field B0) NMR is a form of both absorption and emission spectroscopy, in which resonant radiation is absorbed by an ensemble of nuclei in a sample, a process causing detectable emissions via a magnetically induced electromotive force.

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  • Since the advent of magnetic resonance (MR) imaging, systems with amagnetic field intensity of 1.5 tesla (T) have been deemed the gold standard for different clinical applications in all body areas. Ongoing advances in hardware and software have made theseMRsystems increasingly compact, powerful and versatile, leading to the development of higher magnetic field strength MRsystems (3.0 T) for use in clinical practice and for research purposes. As usually occurs with a new technology, 3.0 T MR imaging units will probably follow the same development trends in the years to come....

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