Maria Evelina Mognaschi

Design optimization of a permanent-magnet excited synchronous machine for electrical automobiles

The paper deals with the automated optimal design of a new synchronous motor particularly suitable for electric vehicles. Identifying the shape of rotor pole and excitation magnets, minimizing the mass/volume and simultaneously maxi- mizing the torque, is the main design goal. The formulation of this problem in terms of a bi-objective optimal shape design problem possibly stimulates the identification of unexplored solutions of practical significance.

Non-Linear Multi-Physics Analysis and Multi-Objective Optimization in Electroheating Applications

The design optimization of an induction heating device is considered. The non-linear multi-physics analysis is carried out by means of finite-element method, while the optimal design problem is solved by NSGA-II genetic algorithm. A comparison with the results obtained by a simplified linear analysis is shown. The original contribution of this paper is the Pareto front identification for a design problem in which the field analysis is multi-physics, dynamic, and non-linear.

Field models and numerical dosimetry inside an extremely-low-frequency electromagnetic bioreactor: the theoretical link between the electromagnetically induced mechanical forces and the biological mechanisms of the cell tensegrity

We have implemented field models and performed a detailed numerical dosimetry inside our extremely-low-frequency electromagnetic bioreactor which has been successfully used in in vitro Biotechnology and Tissue Engineering researches. The numerical dosimetry permitted to map the magnetic induction field (maximum module equal to about 3.3 mT) and to discuss its biological effects in terms of induced electric currents and induced mechanical forces (compression and traction). So, in the frame of the tensegrity-mechanotransduction theory of Ingber, the study of these electromagnetically induced mechanical forces could be, in our opinion, a powerful tool to understand some effects of the electromagnetic stimulation whose mechanisms remain still elusive.

Hybrid excited synchronous machine with flux control possibility

The paper presents simulation and experimental results of an Electric Controlled Permanent Magnet Synchronous (ECPMS) machine that offers an extended magnetic field control capability which makes it suitable for battery electric vehicle drives. Rotor, stator and additional direct current supplied coil of the machine have been analyzed in detail. Control and power supply systems of the machine have been presented. Influence of the additional excitation on the machine performance has also been discussed.

Fast Algorithms for the Design of Complex-Shape Devices in Electromechanics

The analysis of complex-shape electromechanical devices is considered. The use of numerical Schwarz-Christoffel (SC) mapping, coordinated with finite element (FE) analysis, is proposed for fast computation of 2D fields.

β-Adrenergic response is counteracted by extremely-low-frequency pulsed electromagnetic fields in beating cardiomyocytes

Proper β-adrenergic signaling is indispensable for modulating heart frequency. Studies on extremely-low-frequency pulsed electromagnetic field (ELF-PEMF) effects in the heart beat function are contradictory and no definitive conclusions were obtained so far. To investigate the interplay between ELF-PEMF exposure and β-adrenergic signaling, cultures of primary murine neonatal cardiomyocytes and of sinoatrial node were exposed to ELF-PEMF and short and long-term effects were evaluated. The ELF-PEMF generated a variable magnetic induction field of 0-6mT at a frequency of 75Hz. Exposure to 3mT ELF-PEMF induced a decrease of contraction rate, Ca(2+) transients, contraction force, and energy consumption both under basal conditions and after β-adrenergic stimulation in neonatal cardiomyocytes. ELF-PEMF exposure inhibited β-adrenergic response in sinoatrial node (SAN) region. ELF-PEMF specifically modulated β2 adrenergic receptor response and the exposure did not modify the increase of contraction rate after adenylate cyclase stimulation by forskolin. In HEK293T cells transfected with β1 or β2 adrenergic receptors, ELF-PEMF exposure induced a rapid and selective internalization of β2 adrenergic receptor. The β-adrenergic signaling, was reduced trough Gi protein by ELF-PEMF exposure since the phosphorylation level of phospholamban and the PI3K pathway were impaired after isoproterenol stimulation in neonatal cardiomyocytes. Long term effects of ELF-PEMF exposure were assessed in cultures of isolated cardiomyocytes. ELF-PEMF counteracts cell size increase, the generation of binucleated of cardiomyocytes and prevents the up-regulation of hypertrophic markers after β-adrenergic stimulation, indicating an inhibition of cell growth and maturation. These data show that short and long term exposure to ELF-PEMF induces a reduction of cardiac β-adrenergic response at molecular, functional and adaptative levels.

3D FE analysis and control of a submerged arc electric furnace

Purpose of the paper is to study the behaviour of a submerged arc furnace for the production of ferroalloys in order to implement a new voltage-based control system of the furnace. A 3D Finite Element (FE) model has been developed to define an equivalent electric circuit model able to describe the furnace operations. Both field and circuit models are validated by measurements on a furnace installed in an industrial plant. A novel method to control a furnace is proposed.

Electric field computation and measurements in the electroporation of inhomogeneous samples

Abstract In clinical treatments of a class of tumors, e.g. skin tumors, the drug uptake of tumor tissue is helped by means of a pulsed electric field, which permeabilizes the cell membranes. This technique, which is called electroporation, exploits the conductivity of the tissues: however, the tumor tissue could be characterized by inhomogeneous areas, eventually causing a non-uniform distribution of current. In this paper, the authors propose a field model to predict the effect of tissue inhomogeneity, which can affect the current density distribution. In particular, finite-element simulations, considering non-linear conductivity against field relationship, are developed. Measurements on a set of samples subject to controlled inhomogeneity make it possible to assess the numerical model in view of identifying the equivalent resistance between pairs of electrodes.

A Benchmark TEAM Problem for Multi-Objective Pareto Optimization of Electromagnetic Devices

This paper proposes a new benchmark for multi-objective optimization. A solution is furnished which has enabled an extensive search and reliable estimation of the shape of the Pareto front. Field uniformity and sensitivity are considered in the context of robust design. It is argued that the benchmark will provide a challenging target for new algorithms, especially those involving numerical modeling using finite-element codes where the number of objective function calls needs to be minimized for practical design processes.

Source identification based on regularization and evolutionary computing in biomagnetism

Purpose – The purpose of this paper is to develop a source reconstruction technique, applied to a case study in biomagnetism, using both evolutionary optimization and regularization techniques.Design/methodology/approach – The magnetic field, produced by a current dipole in a spheroidal domain modeling the head, is calculated. Although the model is very simple, the magnetic effect of a brain source is appropriately simulated. In order to solve the source identification problem, the following approaches have been implemented: a single‐objective minimization of a residual function, based on an evolutionary algorithm, is applied first; then, the L‐curve criterion for regularization is implemented by means of an iterative search.Findings – A variable number of unknown parameters, defining direction and magnitude of the current dipole, have been considered. As a consequence, several optimization problems are solved: a technique based on the use of the lead field matrix identifies the source with the smallest e...