Search results for "electromagnetic [current]"
showing 10 items of 1008 documents
Noncoaxial Inductance Calculations Without the Vector Potential for Axisymmetric Coils and Planar Coils
2008
This paper presents an exact method for calculating the mutual inductance between a general axisymmetric coil and a second planar coil consisting of either a disk coil or a planar loop of essentially arbitrary shape. The approach is based directly on the magnetic field rather than the vector potential . The paper gives detailed results for two circular loops, a circular loop and an elliptic loop, and a circular loop and an annular disk coil. The method can be extended to cover the cases where all these loops and coils are extruded in the axial direction to give the corresponding solenoids. The method is also applicable to calculations for nuclear radiation detectors.
Limits of validity of siegert’s theorem in the nuclear photoabsorption
1970
Analytical evaluation of integrals occurring in bound-free transitions.
1988
A class of three-dimensional integrals on spatial coordinates of the type occurring in treatments of multiphoton ionization of atoms and of other bound-free transitions is evaluated in closed form for both hydrogenic and Slater-type wave functions. The reported method of evaluation is illustrated with a number of examples, including the multiphoton ionization of hydrogen by a very intense laser field, when the ejected electrons have absorbed more photons than the minimum required to reach the continuum.
Van der Waals Interactions in a Magneto-Dielectric Medium
2007
The van der Waals interaction between two ground-state atoms is calculated for two electrically or magnetically polarizable particles embedded in a dispersive magneto-dielectric medium. Unlike previous calculations which infer the atom-atom interaction from the dilute-medium limit of the macroscopic, many-body van der Waals interaction, the interaction is calculated directly for the system of two atoms in a magneto-dielectric medium. Two approaches are presented, the first based on the quantized electromagnetic field in a dispersive medium without absorption and the second on Green functions that allow for absorption. We show that the correct van der Waals interactions are obtained regardle…
Corrective meshless particle formulations for time domain Maxwell's equations
2007
AbstractIn this paper a meshless approximation of electromagnetic (EM) field functions and relative differential operators based on particle formulation is proposed. The idea is to obtain numerical solutions for EM problems by passing up the mesh generation usually required to compute derivatives, and by employing a set of particles arbitrarily placed in the problem domain. The meshless Smoothed Particle Hydrodynamics method has been reformulated for solving the time domain Maxwell's curl equations. The consistency of the discretized model is investigated and improvements in the approximation are obtained by modifying the numerical process. Corrective algorithms preserving meshless consiste…
Suppression of radiative losses of surface polaritons on nanostructured thin metal films
2005
The strong electromagnetic coupling between surface plasmon polariton modes on opposite interfaces of a finite thickness periodically nanostructured metal film has been studied. Surface polariton dispersion and associated electromagnetic field distributions have been analyzed. It was shown that at a frequency that corresponds to the crossing of film Bloch modes of different symmetries, the radiative losses of surface polaritons that are related to the polaritons' coupling to light during propagation on the structured surface are suppressed.
Combined Effects of 50 Hz Electromagnetic Field and SiO2 Nanoparticles on Oxidative Stress in Plant’s Gametic Cells / Zemfrekvences (50 Hz) Elekromag…
2015
Abstract The paper presents the results of combined effects of an extremely low frequency electromagnetic field (50 Hz) (ELF EMF) and SiO2 nanoparticles on fluorescence of plant gametic cells (immature microspores). The data were recorded by a BD FACSJazz® cell sorter after cell irradiation by blue laser (488 nm). A significant difference of fluorescence was observed between gametic cells after 1 hour incubation in suspension of SiO2 nanoparticles and the control gametic cells. It was observed that fluorescence intensity of gametic cell was higher with ELF EMF treatment in comparison to control cells, but it was statistically significant only for cells treated with electromagnetic radiation…
SEAI: Social Emotional Artificial Intelligence Based on Damasio’s Theory of Mind
2018
A socially intelligent robot must be capable to extract meaningful information in real-time from the social environment and react accordingly with coherent human-like behaviour. Moreover, it should be able to internalise this information, to reason on it at a higher abstract level, build its own opinions independently and then automatically bias the decision-making according to its unique experience. In the last decades, neuroscience research highlighted the link between the evolution of such complex behaviour and the evolution of a certain level of consciousness, which cannot leave out of a body that feels emotions as discriminants and prompters. In order to develop cognitive systems for s…
How Can the Protoconsciousness Hypothesis Contribute to Philosophical Theories of Consciousness and the Self?
2014
In his William James lectures on Dream Consciousness, Allan Hobson provides a rich and multi-faceted introduction to state-of-the-art findings from sleep and dream research, as well as an overview of his own wide-ranging contributions to this field. It is no exaggeration to say that his work has shaped contemporary theories of sleep and dreaming like no other. But he has done even more: by showing how his work on dreaming fits into broader theories of consciousness (Hobson et al. 2000) and psychotic wake states (Hobson 1999), he has repeatedly emphasized its implications for the theoretical understanding of consciousness itself. His long-standing willingness to connect the fields of sleep a…
Concepciones alternativas y dificultades de aprendizaje en electrostática : selección de cuestiones elaboradas para su detección y tratamiento
2021
The work we are presenting here tries to summarise the contributions made by research on the ideas and difficulties of students within the field of Electrostatics. These researches reveal that the concepts introduced in this domain, such as electric field and potential, are necessary prerequisites so as to acquire a scientific vision of electromagnetic phenomena. Thus, taking into account the importance of the concepts involved for a scientific vision of the circuits of continuous current and, in general, of the electromagnetic theory, we think it is important for teachers to have a first idea on which are the most problematic conceptions or at least, those that have been studied most.