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The paper presents a complex process used for obtaining ZnO nanostructures for antireflective coatings. The process is suitable to silicone solar cells and can be used in order to increase their efficiency under low solar radiation, allowing the control of the morphological and optical properties of ZnO nanostructures deposited on glass through ZnO seed layer deposition process. During the research,...
In this paper we propose a piezoelectric ceramic material and its behaviour when integrated into piezoelectric structures. The piezoceramic element has the shape of a disk with diameter of 12 mm while the width is 0.3 mm. On each of the ceramic disk's sides, silver electrodes were attached. Perovskite ceramics based on lead zirconate titanate (PZT) modified with niobium (Nb) were used to obtain the...
This paper presents the driving system of a linear magnetostrictive motor (LMM) that operates in a wide range of frequencies of up to 16 kHz, which is intended for space applications. Accordingly, the design and control of the LMM differs from the classical version, causing changes in electrical driving conception. The LMM drive has two units Pulse Width Modulators (PWM) for the control of the activation...
This paper presents mathematical modeling and numerical simulation results that are part of a study concerning the dynamics of the stator of piezoelectric (PZ) traveling wave (TW) rotating ultrasonic motor. The stator is a PZ composite ring, and the rotor is a metallic ring. The rotational torque is produced by exciting the stator into a flexural traveling wave, transmitted to the rotor through the...
This paper presents a new active electronic protection system that keeps a high temperature superconductor (HTS) coil that is in superconductive state from shifting into normal conduction state (quench). The coil is made of YBCO tape high temperature superconductor, with a critical temperature of 92 K. The superconducting coil is confined to a cryostat, which is vacuumed at about 0.001 mbar to minimize...
In many applications the chip-embedded core of miniature devices is a micro-structured planar spiral power transformer (MPST), and operational and electromagnetic compatibility are key issues to its sizing. Numerical simulation aided design may then be used to solve them. This paper presents mathematical models and numerical simulation results related to sizing the ferrite core, the lumped parameters...
This paper presents the prototype of an apparatus (AMSR) in the 2.5 accuracy class, which operates at 500 Hz, for measuring the in situ resistivity of concrete in the range 5…100 Ωm that is immune to errors due to the polarization phenomena at the interface probe/concrete sample. The direct problem of the electrical resistivity tomography, ERT, is then solved for DC and AC electric fields a sample-specific...
This paper presents mathematical models and numerical simulation results for a notional miniature, planar, spiral transformer (MPST) fabricated in MEMS technology, for galvanic separation, proposed to equip an electric harvesting device (EHD). Two types of core — ferrite and (partially) magnetic nanofluid — are considered, and the lumped parameters (inductances and capacitances) of the MPST are computed...
Compliance with EU regulations for environmental protection sets new performance criteria to fuel injection technology in modern combustion engines for passenger and commercial vehicles. According to EURO-5 norm regulation the quality of the air/fuel mixture combustion depends mainly on an adequate spraying of the fuel, with as fine as possible droplets. The paper introduces the construction, validates...
In this paper there is presented a way of determining and registering the instantaneous power, p(t), in an diagram, for two asynchronous micromotors. These were activated by two phase voltages having the rectangular waveform with pulse width modulation, PWM, and triangular, with variable asymmetry factor, respectively. The deviation from the sinusoidal form of the phase voltage determines not only...
The sensor was made by thick and thin film technology. An alumina substrate 6times6times0.5 mm was used. On the substrate was screen-printed an interdigitated electrode array by Au conductive ink. The sensitive layer the organo-siloxane supramolecular polymers was dissolved in chloroform and was deposed by spin coating on the substrate over electrode in the 200 nm thickness. The sensor was tested...
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