Flower-shaped magnetic nanoparticle powders, synthetized by thermal decomposition, dispersible in... more Flower-shaped magnetic nanoparticle powders, synthetized by thermal decomposition, dispersible in water have been submitted to a physical characterization to evaluate their magnetic behavior in view of their use Magnetic Fluid Hyperthermia treatments
IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society, 2016
Electrochemotherapy is a clinical therapy that uses voltage pulses to electropore cell membranes.... more Electrochemotherapy is a clinical therapy that uses voltage pulses to electropore cell membranes. This paper presents the description of an experimental set-up including the design of a prototype of voltage pulses generator for laboratory experiments in electroporation. The prototype has been designed to study the threshold of electric field that allows the cell membrane electroporation increasing step by step the voltage pulse amplitude. Moreover, the experimental set-up to measure electroporation occurrence is presented and first experimental results are shown.
IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society, 2018
This paper presents the design of a large electrode for electrochemotheray (ECT) treatment of sup... more This paper presents the design of a large electrode for electrochemotheray (ECT) treatment of superficial metastasis, e.g. breast cancer recurrences on chest wall. The device is realized by means of a printed circuit boards realized on a flexible support. The circuit includes two layers one over the other and is modular. This way the size of the electrode can be designed as a function of the treating area. The design includes also the design of ergonomic electrodes realized by using Additive Manufacturing technologies The device has been tested on suitable phantoms in order to evaluate the occurrence of possible drawbacks of the proposed structure.
2017 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering (ISEF) Book of Abstracts, 2017
Electrochemotherapy (ECT) is a local therapy used in clinical practice. This therapy improves the... more Electrochemotherapy (ECT) is a local therapy used in clinical practice. This therapy improves the drug uptake of tumor tissue since it permeabilizes cell membranes by means of an electric field. Nevertheless, the tumor tissue could be characterized by inhomogeneity areas and needle electrodes could be implanted in tissue with different values of conductivity. The authors investigate by means of numerical simulations and experimental tests the effect of tissue inhomogeneity which can affect the current density distribution.
a procedure for the simulation of the magnetic field exposure produced by welding equipments has ... more a procedure for the simulation of the magnetic field exposure produced by welding equipments has been developed using Flux3D tools. Both homogeneous models and human body models have been used in order to compute the induced current density in biological tissues
During recent years, an increased interest in magnetic nanoparticles (NPs) for their use in biome... more During recent years, an increased interest in magnetic nanoparticles (NPs) for their use in biomedical applications, in particular for hyperthermia therapy, has been observed [1]. This promoted the research on synthesis routes that allow better control in NPs shape and size, and, due to the need of obtaining bio-compatible NPs, NPs stabilization in aqueous media. In this study, we synthesized iron oxide magnetic nanoparticles in presence of 2-pyrrolidone, as that acts both as surfactant and solvent [2] and permits to disperse the synthesized nanoparticles in water without any further functionalization. The magnetic NPs were synthesized by thermal decomposition of iron chloride (III) hexahydrate (FeCl3 196H2O) in presence of 2-pyrrolidone; the reagents relative concentration was changed so to access the effect of that on the morphology and on the magnetic properties of the NPs. After the synthesis, the NPs were precipitated and dried, and then dispersed in deionized water with a 10 mg per 1 ml concentration. The magnetic properties of the NPs were investigated using a superconductive quantum interference device (SQUID) magnetometer; M\uf6ssbauer spectroscopy measurements were performed in the 4 K \u2013 300 K range. Size and morphology of the particles were investigated with a transmission electron microscope (TEM), while the heating rate of the magnetic liquids was measured using an inductor suitably designed to maximize the magnetic field uniformity [3]. The sample with the smallest chloride concentration shows nanoparticles with a fine dispersion (NP size ~ 5 nm); an increase in chloride concentration produces flower-shaped NPs, as those presented in fig. 1, where fine nanoparticles are aggregated so to form \u201cflowers\u201d with an average size of 20 nm. A further increase in chloride concentration produces again a fine dispersion of magnetic NPs. The magnetic fluid with flower-shaped NPs turns out to be the most interesting for hyperthermia, as it produces the highest heating rate; the combination of SQUID and M\uf6ssbauer characterization reveals the strong influence of magnetic dipolar interactions on sample magnetic behaviour. From 300 K down to 50 K the M\uf6ssbauer spectra display just a doublet contribution, whose width increases as temperature decreases, possibly due to superparamagnetic relaxation effects; just below 50 K a broad sextet appears. This may suggest that the fine nanoparticles in flower-shaped aggregates behave as single entities, interacting via dipolar and not exchange interactions. Finally, cell culture experiments will be also presented, as NPs have been added to a cell culture in order to evaluate cellular uptake. In particular, TEM analyses revealed a time-dependent uptake of flower-shaped NPs by breast cancer cells. References [1] A. Akbarzadeh et al., Nanoscale Research Letters 7 (2012) 144. [2] A. K. M. Krishnan, IEEE Trans. On Magnetics, 46 (2010) 2523. [3] P. Di Barba et al., IEEE Trans. On Magnetics 46 (2010) 2931
Nowadays, the PV market is still dominated by solar panels that are based on Silicon technology. ... more Nowadays, the PV market is still dominated by solar panels that are based on Silicon technology. The manufacturing process to obtain c-Si solar cells has numerous phases, among which, the casting process is one of the most energy consuming. In PV production the methods of silicon casting which have achieved a strengthened industrial maturity are Czochralski (Cz) technique and Directional Solidification method (DS). Previous works have demonstrated the effectiveness of the induction heating applied to DS processes, mostly in order to improve the control and reduce the process time. In addition, appreciable results have been achieved in producing high quality multi-crystal wafer, mc-wafer, in a prototype of iDSS (induction Directional Solidification System) furnace. In this paper, the application of a magnetic field at lower frequency respect to the actual frequency applied for heating in the furnace is studied in order to analyse the flow motion of the molten Silicon inside the crucible. The goal is to increase the mixing effect and consequently to delay the formation of SiC particles and focusing the impurity concentration in the last phase of solidification. The study has been conducted on numerical models of a G2 iDSS prototype installed at the Laboratory of Electroheat of Padua University.
International Journal of Applied Electromagnetics and Mechanics, 2020
In industrial manufacturing process for tube production the stress relieving is achieved by heati... more In industrial manufacturing process for tube production the stress relieving is achieved by heating the part to be treated at a very uniform temperature. In the paper, the optimized design of an inductor for stress relieving at temperature close to 600° is considered. The design of the inductor is initially performed by means an automated-design using optimization algorithms and objective functions that are minimized. In the range of obtained solutions, some of them appear more promising in terms of heating uniformity. Starting from these improved solutions, a technologically acceptable solution is proposed. This technological feasible solution is selected between the ones obtained by means of a multi-objective optimization procedure and suitably adapted in order to achieve not only the technological targets but also a cost-effective design.
The kerf waste from the sawing of PV silicon wafers is pelletized and then remelted in an inducti... more The kerf waste from the sawing of PV silicon wafers is pelletized and then remelted in an induction furnace. The furnace has a square cross-section quartz crucible, surrounded by graphite susceptors and heated by an induction coil that enables directional solidification of the new ingot. Top and bottom ‘pancake’ coils provide additional temperature control. Once melted, silicon becomes electrically conductive and subject to stirring by induction. To recycle the silicon, particulate impurities (due to the sawing, condensed silicon oxides or carbides) need to be removed. Flow control and the electromagnetic Leenov-Kolin force are used to expel particulates, through a novel dual frequency induction scheme. Three-dimensional numerical modeling captures the electromagnetic, fluid-flow and heat-transfer effects in this problem, in a multi-physics finite volume computational framework. Results are presented for typical electromagnetic, velocity and force fields and conclusions are drawn about the expected effectiveness of the electromagnetic separation system which is still under construction.
A new version of the biogeography-based optimization algorithm is proposed in order to consider m... more A new version of the biogeography-based optimization algorithm is proposed in order to consider multiple objectives. In fact, by exploiting non-dominated sorting of habitats, it is possible to approximate Pareto-optimal solutions in the objective space. The optimal shape design of an electrostatic micromotor, which is a benchmark in the Micro Electro-Mechanical Systems design, is considered as the case study.
A new optimization method, combining design of experiments with evolutionary computing, is propos... more A new optimization method, combining design of experiments with evolutionary computing, is proposed. It handles a set of design variables, the size of which changes during the process. Initially, the most sensitive variables are activated; subsequently, the whole set of variables is activated. The optimal synthesis of a magnetic field for magnetofluid treatment is considered as the case study.
Electrical properties of human soft tissue lipomatous tumors during electrochemotherapy have been... more Electrical properties of human soft tissue lipomatous tumors during electrochemotherapy have been evaluated and the resistance values have been correlated to the histopathological features.
Summary form only given. The magnetic core of a transformer for welding devices has a moving magn... more Summary form only given. The magnetic core of a transformer for welding devices has a moving magnetic shunt. The shunt can assume several different positions to modify the flux leakage values. These transformers are made to supply high current values: saturation of the magnetic core leads to strongly deformed voltage and current.
The design of a transverse flux induction heater requires the solution of a coupled electromagnet... more The design of a transverse flux induction heater requires the solution of a coupled electromagnetic and thermal numerical model. In order to validate a finite element 3D model, where a novel formulation based on edge elements have been used for the electromagnetic solution, some comparisons are presented between experimental temperature distributions and calculated data. The temperature distributions in a stainless
2006 IEEE Instrumentation and Measurement Technology Conference Proceedings, 2006
A technique for the estimation of the magnetic field intensity emitted by industrial installation... more A technique for the estimation of the magnetic field intensity emitted by industrial installations is presented. The method is best-suited for investigation of environmental magnetic field for health purposes. Simulation and measurement case-studies supporting the provided theoretical results are discussed
Flower-shaped magnetic nanoparticle powders, synthetized by thermal decomposition, dispersible in... more Flower-shaped magnetic nanoparticle powders, synthetized by thermal decomposition, dispersible in water have been submitted to a physical characterization to evaluate their magnetic behavior in view of their use Magnetic Fluid Hyperthermia treatments
IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society, 2016
Electrochemotherapy is a clinical therapy that uses voltage pulses to electropore cell membranes.... more Electrochemotherapy is a clinical therapy that uses voltage pulses to electropore cell membranes. This paper presents the description of an experimental set-up including the design of a prototype of voltage pulses generator for laboratory experiments in electroporation. The prototype has been designed to study the threshold of electric field that allows the cell membrane electroporation increasing step by step the voltage pulse amplitude. Moreover, the experimental set-up to measure electroporation occurrence is presented and first experimental results are shown.
IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society, 2018
This paper presents the design of a large electrode for electrochemotheray (ECT) treatment of sup... more This paper presents the design of a large electrode for electrochemotheray (ECT) treatment of superficial metastasis, e.g. breast cancer recurrences on chest wall. The device is realized by means of a printed circuit boards realized on a flexible support. The circuit includes two layers one over the other and is modular. This way the size of the electrode can be designed as a function of the treating area. The design includes also the design of ergonomic electrodes realized by using Additive Manufacturing technologies The device has been tested on suitable phantoms in order to evaluate the occurrence of possible drawbacks of the proposed structure.
2017 18th International Symposium on Electromagnetic Fields in Mechatronics, Electrical and Electronic Engineering (ISEF) Book of Abstracts, 2017
Electrochemotherapy (ECT) is a local therapy used in clinical practice. This therapy improves the... more Electrochemotherapy (ECT) is a local therapy used in clinical practice. This therapy improves the drug uptake of tumor tissue since it permeabilizes cell membranes by means of an electric field. Nevertheless, the tumor tissue could be characterized by inhomogeneity areas and needle electrodes could be implanted in tissue with different values of conductivity. The authors investigate by means of numerical simulations and experimental tests the effect of tissue inhomogeneity which can affect the current density distribution.
a procedure for the simulation of the magnetic field exposure produced by welding equipments has ... more a procedure for the simulation of the magnetic field exposure produced by welding equipments has been developed using Flux3D tools. Both homogeneous models and human body models have been used in order to compute the induced current density in biological tissues
During recent years, an increased interest in magnetic nanoparticles (NPs) for their use in biome... more During recent years, an increased interest in magnetic nanoparticles (NPs) for their use in biomedical applications, in particular for hyperthermia therapy, has been observed [1]. This promoted the research on synthesis routes that allow better control in NPs shape and size, and, due to the need of obtaining bio-compatible NPs, NPs stabilization in aqueous media. In this study, we synthesized iron oxide magnetic nanoparticles in presence of 2-pyrrolidone, as that acts both as surfactant and solvent [2] and permits to disperse the synthesized nanoparticles in water without any further functionalization. The magnetic NPs were synthesized by thermal decomposition of iron chloride (III) hexahydrate (FeCl3 196H2O) in presence of 2-pyrrolidone; the reagents relative concentration was changed so to access the effect of that on the morphology and on the magnetic properties of the NPs. After the synthesis, the NPs were precipitated and dried, and then dispersed in deionized water with a 10 mg per 1 ml concentration. The magnetic properties of the NPs were investigated using a superconductive quantum interference device (SQUID) magnetometer; M\uf6ssbauer spectroscopy measurements were performed in the 4 K \u2013 300 K range. Size and morphology of the particles were investigated with a transmission electron microscope (TEM), while the heating rate of the magnetic liquids was measured using an inductor suitably designed to maximize the magnetic field uniformity [3]. The sample with the smallest chloride concentration shows nanoparticles with a fine dispersion (NP size ~ 5 nm); an increase in chloride concentration produces flower-shaped NPs, as those presented in fig. 1, where fine nanoparticles are aggregated so to form \u201cflowers\u201d with an average size of 20 nm. A further increase in chloride concentration produces again a fine dispersion of magnetic NPs. The magnetic fluid with flower-shaped NPs turns out to be the most interesting for hyperthermia, as it produces the highest heating rate; the combination of SQUID and M\uf6ssbauer characterization reveals the strong influence of magnetic dipolar interactions on sample magnetic behaviour. From 300 K down to 50 K the M\uf6ssbauer spectra display just a doublet contribution, whose width increases as temperature decreases, possibly due to superparamagnetic relaxation effects; just below 50 K a broad sextet appears. This may suggest that the fine nanoparticles in flower-shaped aggregates behave as single entities, interacting via dipolar and not exchange interactions. Finally, cell culture experiments will be also presented, as NPs have been added to a cell culture in order to evaluate cellular uptake. In particular, TEM analyses revealed a time-dependent uptake of flower-shaped NPs by breast cancer cells. References [1] A. Akbarzadeh et al., Nanoscale Research Letters 7 (2012) 144. [2] A. K. M. Krishnan, IEEE Trans. On Magnetics, 46 (2010) 2523. [3] P. Di Barba et al., IEEE Trans. On Magnetics 46 (2010) 2931
Nowadays, the PV market is still dominated by solar panels that are based on Silicon technology. ... more Nowadays, the PV market is still dominated by solar panels that are based on Silicon technology. The manufacturing process to obtain c-Si solar cells has numerous phases, among which, the casting process is one of the most energy consuming. In PV production the methods of silicon casting which have achieved a strengthened industrial maturity are Czochralski (Cz) technique and Directional Solidification method (DS). Previous works have demonstrated the effectiveness of the induction heating applied to DS processes, mostly in order to improve the control and reduce the process time. In addition, appreciable results have been achieved in producing high quality multi-crystal wafer, mc-wafer, in a prototype of iDSS (induction Directional Solidification System) furnace. In this paper, the application of a magnetic field at lower frequency respect to the actual frequency applied for heating in the furnace is studied in order to analyse the flow motion of the molten Silicon inside the crucible. The goal is to increase the mixing effect and consequently to delay the formation of SiC particles and focusing the impurity concentration in the last phase of solidification. The study has been conducted on numerical models of a G2 iDSS prototype installed at the Laboratory of Electroheat of Padua University.
International Journal of Applied Electromagnetics and Mechanics, 2020
In industrial manufacturing process for tube production the stress relieving is achieved by heati... more In industrial manufacturing process for tube production the stress relieving is achieved by heating the part to be treated at a very uniform temperature. In the paper, the optimized design of an inductor for stress relieving at temperature close to 600° is considered. The design of the inductor is initially performed by means an automated-design using optimization algorithms and objective functions that are minimized. In the range of obtained solutions, some of them appear more promising in terms of heating uniformity. Starting from these improved solutions, a technologically acceptable solution is proposed. This technological feasible solution is selected between the ones obtained by means of a multi-objective optimization procedure and suitably adapted in order to achieve not only the technological targets but also a cost-effective design.
The kerf waste from the sawing of PV silicon wafers is pelletized and then remelted in an inducti... more The kerf waste from the sawing of PV silicon wafers is pelletized and then remelted in an induction furnace. The furnace has a square cross-section quartz crucible, surrounded by graphite susceptors and heated by an induction coil that enables directional solidification of the new ingot. Top and bottom ‘pancake’ coils provide additional temperature control. Once melted, silicon becomes electrically conductive and subject to stirring by induction. To recycle the silicon, particulate impurities (due to the sawing, condensed silicon oxides or carbides) need to be removed. Flow control and the electromagnetic Leenov-Kolin force are used to expel particulates, through a novel dual frequency induction scheme. Three-dimensional numerical modeling captures the electromagnetic, fluid-flow and heat-transfer effects in this problem, in a multi-physics finite volume computational framework. Results are presented for typical electromagnetic, velocity and force fields and conclusions are drawn about the expected effectiveness of the electromagnetic separation system which is still under construction.
A new version of the biogeography-based optimization algorithm is proposed in order to consider m... more A new version of the biogeography-based optimization algorithm is proposed in order to consider multiple objectives. In fact, by exploiting non-dominated sorting of habitats, it is possible to approximate Pareto-optimal solutions in the objective space. The optimal shape design of an electrostatic micromotor, which is a benchmark in the Micro Electro-Mechanical Systems design, is considered as the case study.
A new optimization method, combining design of experiments with evolutionary computing, is propos... more A new optimization method, combining design of experiments with evolutionary computing, is proposed. It handles a set of design variables, the size of which changes during the process. Initially, the most sensitive variables are activated; subsequently, the whole set of variables is activated. The optimal synthesis of a magnetic field for magnetofluid treatment is considered as the case study.
Electrical properties of human soft tissue lipomatous tumors during electrochemotherapy have been... more Electrical properties of human soft tissue lipomatous tumors during electrochemotherapy have been evaluated and the resistance values have been correlated to the histopathological features.
Summary form only given. The magnetic core of a transformer for welding devices has a moving magn... more Summary form only given. The magnetic core of a transformer for welding devices has a moving magnetic shunt. The shunt can assume several different positions to modify the flux leakage values. These transformers are made to supply high current values: saturation of the magnetic core leads to strongly deformed voltage and current.
The design of a transverse flux induction heater requires the solution of a coupled electromagnet... more The design of a transverse flux induction heater requires the solution of a coupled electromagnetic and thermal numerical model. In order to validate a finite element 3D model, where a novel formulation based on edge elements have been used for the electromagnetic solution, some comparisons are presented between experimental temperature distributions and calculated data. The temperature distributions in a stainless
2006 IEEE Instrumentation and Measurement Technology Conference Proceedings, 2006
A technique for the estimation of the magnetic field intensity emitted by industrial installation... more A technique for the estimation of the magnetic field intensity emitted by industrial installations is presented. The method is best-suited for investigation of environmental magnetic field for health purposes. Simulation and measurement case-studies supporting the provided theoretical results are discussed
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Papers by F. Dughiero