scholarly journals ANALYTICAL CALCULATIONS OF ELECTROMAGNETIC QUANTITIES FOR SLOTTED BRUSHLESS MACHINES WITH SURFACE-INSET MAGNETS

2017 ◽  
Vol 72 ◽  
pp. 49-65 ◽  
Author(s):  
Akbar Rahideh ◽  
Hossein Moayed-Jahromi ◽  
Mohamed Mardaneh ◽  
Frederic Dubas ◽  
Theodosios Korakianitis
2009 ◽  
Vol 2009 ◽  
pp. 1-20 ◽  
Author(s):  
Rostyslav Sklyar

The proposal to measure the biosignal values of different origins with advanced nanosensors of electromagnetic quantities is justified when allowing for superconducting abilities of the devices. They are composed in full-scale arrays. The said arrays can be both implantable into ionic channels of an organism and sheathed on the sources of the electromagnetic emanation. Nanowired head sensors function both in passive mode for picking up the biosignals and with additional excitation of a defined biomedium through the same head (in reverse). The designed variety of bio-nanosensors allow interfacing a variety of biosignals with the external systems, also with a possibility to control the exposure on an organism by artificially created signals. The calculated signals lies in the range of to 5 V, molecules or magnetic beads,  pH, and stream speed  m/s, flow  m/s, and haemoglobin concentration of  . The sensitivity of this micro- or nanoscope can be estimated as (/√Hz) with SNR equal to . The sensitivity of an advanced first-order biogradiometer is equal to 3 fT/√Hz. The smallest resolvable change in magnetic moment detected by this system in the band 10 Hz is 1 fJ/T.


Author(s):  
C.H.H.M. Custers ◽  
J.W. Jansen ◽  
M.C. van Beurden ◽  
E.A. Lomonova

PurposeThe purpose of this paper is to describe a semi-analytical modeling technique to predict eddy currents in three-dimensional (3D) conducting structures with finite dimensions. Using the developed method, power losses and parasitic forces that result from eddy current distributions can be computed.Design/methodology/approachIn conducting regions, the Fourier-based solutions are developed to include a spatially dependent conductivity in the expressions of electromagnetic quantities. To validate the method, it is applied to an electromagnetic configuration and the results are compared to finite element results.FindingsThe method shows good agreement with the finite element method for a large range of frequencies. The convergence of the presented model is analyzed.Research limitations/implicationsBecause of the Fourier series basis of the solution, the results depend on the considered number of harmonics. When conducting structures are small with respect to the spatial period, the number of harmonics has to be relatively large.Practical implicationsBecause of the general form of the solutions, the technique can be applied to a wide range of electromagnetic configurations to predict, e.g. eddy current losses in magnets or wireless energy transfer systems. By adaptation of the conductivity function in conducting regions, eddy current distributions in structures containing holes or slit patterns can be obtained.Originality/valueWith the presented technique, eddy currents in conducting structures of finite dimensions can be modeled. The semi-analytical model is for a relatively low number of harmonics computationally faster than 3D finite element methods. The method has been validated and shown to be computationally accurate.


Geophysics ◽  
1946 ◽  
Vol 11 (3) ◽  
pp. 383-384
Author(s):  
Glenn J. Baker

In the course of theoretical work and experimentation in the field it was my experience that the use of the m.k.s. system of units resulted in a saving of labor and also helped to clarify some concepts. The purpose of preparing my paper was, as stated, to present a conversion table and to bring to the attention of others the advantages of the m.k.s. system. These considerations, and an enterprising program committee, constituted my only “irresistible urge to publish something on the subject.”


Physics ◽  
2021 ◽  
Vol 3 (4) ◽  
pp. 1054-1087
Author(s):  
Slobodan Babic

In this paper, the improved and the new analytical and semi-analytical expressions for calculating the magnetic vector potential, magnetic field, magnetic force, mutual inductance, torque, and stiffness between two inclined current-carrying arc segments in air are given. The expressions are obtained either in the analytical form over the incomplete elliptic integrals of the first and the second kind or by the single numerical integration of some elliptical integrals of the first and the second kind. The validity of the presented formulas is proved from the particular cases when the inclined circular loops are addressed. We mention that all formulas are obtained by the integral approach, except the stiffness, which is found by the derivative of the magnetic force. The novelty of this paper is the treatment of the inclined circular carting-current arc segments for which the calculations of the previously mentioned electromagnetic quantities are given.


2019 ◽  
Vol 127 (7) ◽  
pp. 82
Author(s):  
Н.Н. Розанов ◽  
М.В. Архипов ◽  
Р.М. Архипов ◽  
Н.А. Веретенов ◽  
А.В. Пахомов ◽  
...  

AbstractA review of results of an investigation of the theory of optical wave packets with extreme properties with respect to a controllable pulse shape or to the complexity of the internal structure of radiation beam pulses is presented. Special attention is paid to the manifestations of dissipative effects of the electromagnetic energy inflow and outflow. Precisely these factors lead to peculiar rules of conservation of purely electromagnetic quantities in dissipative media, in which the electromagnetic energy irreversibly decreases in the case of absorption and increases with gain. These rules impose certain restrictions on the possibility of transformation of the shape of pulses and allow one to qualitative describe their evolution. A higher efficiency of the action of unipolar or quasi-unipolar radiation pulses on classical and quantum microobjects is shown and possible ways of formation of these pulses are discussed. For bulk laser media with saturable absorption, the topological properties of localized radiation structures and their transformations with a smooth change in the parameters of the medium (pump level) are described. The preservation of the topological structure upon changes in parameters within the stability range yields the possibility of their distinguishing when coding information by topological solitons of the considered type.


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