Mojtaba Ghodsi - Academia.edu (original) (raw)
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Papers by Mojtaba Ghodsi
International Journal of the Physical Sciences, 2011
Advances in Nanocomposite Research, Aug 6, 2014
Http Dx Doi Org 10 1080 10426914 2014 921710, Jul 7, 2014
Physica C, 2006
In this paper we propose a new experimental method to investigate the principle of 'Mixed-μ' levi... more In this paper we propose a new experimental method to investigate the principle of 'Mixed-μ' levitation systems. To confirm our claim, we measured the attractive force and the variation of flux passing through both, the HTS sample and the face surface of iron yoke, when the yoke is approached/retreated to the surface of field-cooled HTS sample. It is revealed that when the diameter of the yoke is less than the diameter of the HTS, in the small gap by reducing the gap, the flux which passes through the face surface of the yoke and consequently the attractive force will decrease. Therefore, stable levitation is achievable. However, when the diameter of yoke is equal to the diameter of the HTS, the magnetic flux will not decrease for a reducing gap and stable levitation is unfeasible. Briefly, stable levitation is achievable when the yoke diameter is less than the HTS's diameter. Additionally, as the yoke is approached to the HTS the flux variation of the HTS in 77 K is negligible compare to the flux variation of the HTS in the room temperature. Therefore, in superconductivity state the pinned fluxes in the HTS samples remain approximately constant and the HTS acts as a 'magnetic isolator'. This specification can be used to simulate the behavior of field-cooled HTS by the FEM software.
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, and Civil Infrastructure 2016, 2016
The International Journal of Advanced Manufacturing Technology, 2014
Journal of Magnetism and Magnetic Materials, 2015
Structural health monitoring of stationary and moving structures has been considered based on ele... more Structural health monitoring of stationary and moving structures has been considered based on electromechanical impedance/admittance (EMI/EMA) spectrum of deposited piezoelectric thick films as wafer active transducers. This method is one of the effective approaches to predict the probable damages in a variety of sensitive structures like turbofans, compressors, and specifically titanium or super alloy blades in aerospace industries. In this study, thick piezoelectric films of a) PbZr0.52Ti0.48O3- PZT, b) Bi4Ti3O12-BiT, c) PZT-PZT composite, and d) PZT-BiT composite, were deposited on the convex surfaces of nickel-based super alloy blades Ruston-TA 1750 (IN738) and Pratt&Whitney JT8D (IN718) for structural health monitoring with different thicknesses and properties using photochemical metal-organic deposition and hybrid sol-gel techniques. ...
Electrostatic motors are presented special advantages compare to electromagnetic motors such as l... more Electrostatic motors are presented special advantages compare to electromagnetic motors such as light-weight, compactness and simple to fabricating. Due to these capabilities, recently, many researchers are working on electrostatic motors to make them applicable in industries. Accordingly, in this paper a new design idea for these motors is investigated theoretically and experimentally. This motor has driving electrodes on both rotor and stator, however, no wire is attached to rotor and signals are transferred to rotor using the induction electrodes. Modeling is implemented to study the effective parameters on performance. Then, using the modeling results, the design parameters are optimized using numerical method to improve the torque and minimize the ripple. Optimization findings are identified an optimum value for ratio of width to gap for driving electrodes and an optimum value for ratio of induction electrodes surface to total surface. Finally, the motor performance is evaluate...
Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2015, 2015
Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2015, 2015
Journal of Magnetism and Magnetic Materials, 2015
Smart Materials Research, 2014
IEEE Transactions on Magnetics, 2015
International Journal of the Physical Sciences, 2011
Advances in Nanocomposite Research, Aug 6, 2014
Http Dx Doi Org 10 1080 10426914 2014 921710, Jul 7, 2014
Physica C, 2006
In this paper we propose a new experimental method to investigate the principle of 'Mixed-μ' levi... more In this paper we propose a new experimental method to investigate the principle of 'Mixed-μ' levitation systems. To confirm our claim, we measured the attractive force and the variation of flux passing through both, the HTS sample and the face surface of iron yoke, when the yoke is approached/retreated to the surface of field-cooled HTS sample. It is revealed that when the diameter of the yoke is less than the diameter of the HTS, in the small gap by reducing the gap, the flux which passes through the face surface of the yoke and consequently the attractive force will decrease. Therefore, stable levitation is achievable. However, when the diameter of yoke is equal to the diameter of the HTS, the magnetic flux will not decrease for a reducing gap and stable levitation is unfeasible. Briefly, stable levitation is achievable when the yoke diameter is less than the HTS's diameter. Additionally, as the yoke is approached to the HTS the flux variation of the HTS in 77 K is negligible compare to the flux variation of the HTS in the room temperature. Therefore, in superconductivity state the pinned fluxes in the HTS samples remain approximately constant and the HTS acts as a 'magnetic isolator'. This specification can be used to simulate the behavior of field-cooled HTS by the FEM software.
Nondestructive Characterization and Monitoring of Advanced Materials, Aerospace, and Civil Infrastructure 2016, 2016
The International Journal of Advanced Manufacturing Technology, 2014
Journal of Magnetism and Magnetic Materials, 2015
Structural health monitoring of stationary and moving structures has been considered based on ele... more Structural health monitoring of stationary and moving structures has been considered based on electromechanical impedance/admittance (EMI/EMA) spectrum of deposited piezoelectric thick films as wafer active transducers. This method is one of the effective approaches to predict the probable damages in a variety of sensitive structures like turbofans, compressors, and specifically titanium or super alloy blades in aerospace industries. In this study, thick piezoelectric films of a) PbZr0.52Ti0.48O3- PZT, b) Bi4Ti3O12-BiT, c) PZT-PZT composite, and d) PZT-BiT composite, were deposited on the convex surfaces of nickel-based super alloy blades Ruston-TA 1750 (IN738) and Pratt&Whitney JT8D (IN718) for structural health monitoring with different thicknesses and properties using photochemical metal-organic deposition and hybrid sol-gel techniques. ...
Electrostatic motors are presented special advantages compare to electromagnetic motors such as l... more Electrostatic motors are presented special advantages compare to electromagnetic motors such as light-weight, compactness and simple to fabricating. Due to these capabilities, recently, many researchers are working on electrostatic motors to make them applicable in industries. Accordingly, in this paper a new design idea for these motors is investigated theoretically and experimentally. This motor has driving electrodes on both rotor and stator, however, no wire is attached to rotor and signals are transferred to rotor using the induction electrodes. Modeling is implemented to study the effective parameters on performance. Then, using the modeling results, the design parameters are optimized using numerical method to improve the torque and minimize the ripple. Optimization findings are identified an optimum value for ratio of width to gap for driving electrodes and an optimum value for ratio of induction electrodes surface to total surface. Finally, the motor performance is evaluate...
Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2015, 2015
Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2015, 2015
Journal of Magnetism and Magnetic Materials, 2015
Smart Materials Research, 2014
IEEE Transactions on Magnetics, 2015