Search results for "put"
showing 10 items of 55942 documents
Design and analysis of non-linear circuit with tunnel diode for hybrid control systems
2018
Electric circuits with tunnel diode's represent a classical example of dynamic systems with nonlinearities, which feature piecewise negative damping and multiple equilibria and, as consequence, nontrivial trajectories in the state-space. In this paper, we describe the experimental design and analysis of an electrical circuit, including a tunnel diode, allowing for a storage behavior with bistable output voltage states - low and high. The system is modeled for simulation and an experimental setup is designed and implemented in order to run a formal verification on different tools, applying a variety of hybrid control methods. The nonlinear diode's characteristic curve is experimentally deter…
Experimental investigation on different rainfall energy harvesting structures
2018
In this paper proposes an experimental comparison between different rainfall harvesting devices and the study of the corresponding electrical rectifying circuit. More in detail, three harvesting structures are considered: the cantilever, the bridge and the floating circle. For each of the proposed structure, different waveforms have been acquired and discussed. The processed data have been compared in order to suggest the best choice for the rectifying circuit, from the simplest one to the most endorsed in the technical literature.
The influence of AlN buffer over the polarity and the nucleation of self-organized GaN nanowires
2015
We experimentally investigate the influence of AlN buffer growth on the nucleation and the polarity of a self-organized assembly of GaN nanowires (NWs) grown on Si. Two complementary growth mechanisms for AlN buffer deposited on Si are demonstrated. Both emphasize the aggregation of Si on the AlN surface and the growth of large cubic crystallites, namely, AlN pedestals. Further growths of GaN NWs assembly reveal that the GaN 2D layer found at the bottom of the NW assembly is the result of the coalescence of Ga-polar pyramids, whereas AlN pedestals are observed as preferential but not exclusive NW nucleation sites. NWs are N-polar or exhibit inversion domains with a Ga-polar core/N-polar she…
Measurements on partial discharge in on‐site operating power transformer: a case study
2018
This study presents the case study of a substation in-service power transformer referred to the on-site partial discharge (PD) detection and evaluation methods. An original methodology for simultaneous application of three methods is proposed: electrical, acoustic and ultra-high frequency. Transformer is powered by the power grid and no external generator is required according to the proposed methodology. Furthermore, several possibilities of applying these concurrent measurements and benefits of such solution in terms of result interpretation, interference resistance and on-site measurement applicability are indicated. The proposed methodology allows for a fast, accurate and secure PD diag…
FPGA based digital lock-in amplifier for fNIRS systems
2018
Lock-In Amplifiers (LIA) represent a powerful technique helping to improve signals detectability when low signal to noise ratios are experienced. Continuous Wave functional Near Infrared Spectroscopy (CW-fNIRS) systems for e-health applications usually suffer of poor detection due to the presence of strong attenuations of the optical recovering path and therefore small signals are severely dipped in a high noise floor. In this work a digital LIA system, implemented on a Zynq® Field Programmable Gate Array (FPGA), has been designed and tested to verify the quality of the developed solution, when applied in fNIRS systems. Experimental results have shown the goodness of the proposed solutions.
The filter and calibration wheel for the ATHENA wide field imager
2016
The planned filter and calibration wheel for the Wide Field Imager (WFI) instrument on Athena is presented. With four selectable positions it provides the necessary functions, in particular an UV/VIS blocking filter for the WFI detectors and a calibration source. Challenges for the filter wheel design are the large volume and mass of the subsystem, the implementation of a robust mechanism and the protection of the ultra-thin filter with an area of 160 mm square. This paper describes performed trade-offs based on simulation results and describes the baseline design in detail. Reliable solutions are envisaged for the conceptual design of the filter and calibration wheel. Four different varian…
Modeling Stator Winding Inter-Turn Short Circuit Faults in PMSMs including Cross Effects
2020
Author's accepted manuscript. © 2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. This paper presents a detailed analysis of stator winding inter-turn Short Circuit (ITSC) faults, taking the cross effects in the three phases of a permanent magnet synchronous motor (PMSM) into account by considering insulation degradation resistances. A PMSM with series coils in eac…
Custom measurement system for memristor characterisation
2021
Abstract A cheap, compact and customisable characterisation system for memristor devices, working between ± 10 V, is presented. SPICE (Simulation Program with Integrated Circuit Emphasis) simulations are performed to verify the circuit feasibility and a proper software is developed to drive the system. The potentiality of the realised system is tested by performing several electrical measurements on both Cu/HfO2/Pt memristors and two-terminals commercial devices.
Dynamic Consensus: Increasing Blockchain Adaptability to Enterprise Applications
2020
Decentralization powered by blockchain is validated for its capability to build trust like no other computational system before. The evolution of blockchain models has opened new use-cases that are becoming operational in many industry fields such as: energy, healthcare, banking, cross-border trade, aerospace, supply chain, and others. The core component of a decentralized architecture is the consensus algorithm - the set of rules that ensures an automated and fair agreement between the actors in the same network. Classic consensus algorithms are tailored to solve specific problems, but in an open ecosystem, each business case is unique and needs a certain level of customization. This paper…
A General Mathematical Formulation for the Determination of Differential Leakage Factors in Electrical Machines with Symmetrical and Asymmetrical Ful…
2018
This paper presents a simple and general mathematical formulation for the determination of the differential leakage factor for both symmetrical and asymmetrical full and dead-coil windings of electrical machines. The method can be applied to all multiphase windings and considers Gorges polygons in conjunction with masses geometry in order to find an easy and affordable way to compute the differential leakage factor, avoiding the adoption of traditional methods that refer to the Ossanna's infinite series, which has to be obviously truncated under the bound of a predetermined accuracy. Moreover, the method described in this paper allows the easy determination of both the minimum and maximum v…