Search results for "Magnetics"

Experimental comparison of two control algorithms for low-saliency ratio interior permanent magnet synchronous motors

2018

In this paper, an experimental investigation on the comparison between the Maximum Torque Per Ampere (MTPA) and the Field Orientation Control (FOC) algorithms for interior permanent magnet synchronous machines (IPMSMs) is described, analyzed and discussed. This investigation was carried out on a small-power IPMSM with low saliency ratio. More in detail, after a previous simulation study, the control techniques have been experimentally implemented and validated through means of a dSPACE® rapid prototyping system. The performances of the two algorithms have been evaluated and compared, obtaining interesting results.

Nvidia CUDA parallel processing of large FDTD meshes in a desktop computer

2020

The Finite Difference in Time Domain numerical (FDTD) method is a well know and mature technique in computational electrodynamics. Usually FDTD is used in the analysis of electromagnetic structures, and antennas. However still there is a high computational burden, which is a limitation for use in combination with optimization algorithms. The parallelization of FDTD to calculate in GPU is possible using Matlab and CUDA tools. For instance, the simulation of a planar array, with a three dimensional FDTD mesh 790x276x588, for 6200 time steps, takes one day -elapsed time- using the CPU of an Intel Core i3 at 2.4GHz in a personal computer, 8Gb RAM. This time is reduced 120 times when the calcula…

Integrated geophysical surveys in the tarragona cathedral

2009

An integrated geophysical survey has been conducted at the Tarragona’s Cathedral (Catalonia, NE Spain) with the aim to detect the existence of archaeological remains of the Roman’s temple devoted to August. Many hypotheses have been proposed about its possible location, the last ones regarding the inner part of the Cathedral, which is one of the most famous temple of Spain (12th century) evolving from Romanesque to Gothic styles. A project including electrical resistivity tomography (ERT), ground probing radar (GPR) and frequency domain electromagnetics (FDEM) has been planned over one year and conducted during a week of intensive field survey. From all the methods applied, both ERT and GPR…

Effects of an earth-strength magnetic field on pineal melatonin synthesis in pigeons

1987

A spatially resolved investigation of the local, micro-magnetic domain structure of single and polycrystalline Co2FeSi

2007

The Heusler compound Co2FeSi is a promising material for magneto-electronic devices. With a Curie temperature of 1100?K and a saturation magnetization of 6?Bohr magnetons and a high spin polarization at the Fermi edge it fulfils the essential requirements for magnetic sensors or spin valve structures. An essential feature for such devices is the micro-magnetic domain structure. X-ray magnetic circular dichroism?photo emission electron microscopy has been used for a direct observation of the domain structure of single- and polycrystalline samples. The polycrystalline material exhibits a micro-magnetic ripple structure, as it is well known for pure Co and other polycrystalline Heusler compoun…

Reversible effect of magnetic fields on human lymphocyte activation patterns: different sensitivity of naive and memory lymphocyte subsets.

2009

The aim of this study was to investigate the influence of 50 Hz magnetic or static magnetic fields of 0.5 mT on subsets of human CD4(+) T cells in terms of cytokine release/content, cell proliferation and intracellular free calcium concentration. CD4(+) T cells can be divided into different subsets on the basis of surface marker expression, such as CD45, and T cells can be divided into naive (CD45RA(+)) and memory (CD45RA(-)) cells. In this study, the effects of magnetic fields after 24 and 48 h of cell culture were analyzed. We found that the CD4(+)CD45RA(-) T subset were more sensitive after 2 h of exposure. Decreases in the release/content of IFN-gamma, in cell proliferation and in intra…

When nominal features are marked on verbs: A transcranial magnetic stimulation study

2006

It has been claimed that verb processing (as opposed to noun processing) is subserved by specific neural circuits in the left prefrontal cortex. In this study, we took advantage of the unusual grammatical characteristics of clitic pronouns in Italian (e.g., lo and la in portalo and portala 'bring it [masculine]/[feminine]', respectively)-the fact that clitics have both nominal and verbal characteristics, to explore the neural correlates of verb and clitic processing. We used repetitive transcranial magnetic stimulation (rTMS) to suppress the excitability of the left prefrontal cortex and to assess its role in producing verb+det+noun and verb+clitic phrases. Results showed an interference ef…

Cortico-bulbar fibers to orofacial muscles: recordings with enoral surface electrodes.

1997

A new recording technique was developed to eliminate current problems on recording transcranial evoked facial muscle responses. A fork-shaped device equipped with 2 pairs of Ag/AgCl-electrodes was inserted enorally at the buccinator muscle level. Advantages offered by this method comprise clearly defined negative deflection of the compound muscle action potential, lack of relevant volume conduction from adjacent muscles, reliability of amplitude criteria, absence of interfering stimulus artifacts, easy achievement of preactivation, and noninvasive recording by surface electrodes. In 43 healthy subjects transcranial magnetic stimulation evoked contralateral responses at a mean latency and me…

Illusory contours and specific regions of human extrastriate cortex: evidence from rTMS.

2003

Functional magnetic resonance imaging studies showed that perception of illusory contours is associated with extrastriate cortex activation prevailing on the right side. 1 Hz repetitive transcranial magnetic stimulation (rTMS) is able to induce lasting inhibition of cortical activity. The objective of the study was to investigate the role of extrastriate cortex in illusory contour perception inducing 1 Hz rTMS interference in healthy subjects. Eight healthy subjects underwent 1 Hz rTMS (600 pulses) through a figure-of-eight coil over right and left occipital cortex (O1 and O2 of 10/20 EEG system); sham magnetic stimulation on the same sites and right motor cortex rTMS (in three subjects) we…

Magnetic molecularly imprinted polymers for the selective determination of cocaine by ion mobility spectrometry

2018

Abstract Magnetic molecularly imprinted polymers (MMIPs) were prepared for cocaine recognition by bulk polymerization in the presence of magnetic nanoparticles (MNPs). Two reagents (polyethylene glycol (PEG) and 3-(trimethoxysilyl)propyl methacrylate (V)) were used for MNPs modification. MMIPs were characterized and compared in terms of loading capacity, reusability, accuracy and precision for the extraction of cocaine from saliva samples. It was observed that V-MMIPs gave higher physical stability than PEG-MMIPs. Thus, V-MMIP were used for the analysis of cocaine users saliva. The developed procedure based on ion mobility spectrometry (IMS) provided limits of detection and quantification o…