Search results for "CIRCUIT"
showing 10 items of 936 documents
Large bulk Micromegas detectors for TPC applications
2009
A large volume TPC will be used in the near future in a variety of experiments including T2K. The bulk Micromegas detector for this TPC is built using a novel production technique particularly suited for compact, thin and robust low mass detectors. The capability to pave a large Surface with a simple mounting Solution and small dead space is of particular interest for these applications. We have built several large bulk Micromegas detectors (36 x 34 cm(2)) and we have tested one in the former HARP field cage with a magnetic field. Prototypes cards of the T2K front end electronics, based on the AFTER ASIC chip, have been used in this TPC test for the first time. Cosmic ray data have been acq…
Optimal Configuration for N-Dimensional Twin Torus Networks
2014
Torus topology is one of the most common topologies used in the current largest supercomputers. Although 3D torus is widely used, recently some supercomputers in the Top500 list have been built using networks with topologies of five or six dimensions. To obtain an nD torus, 2n ports per node are needed. These ports can be offered by a single or several cards per node. In the second case, there are multiple ways of assigning the dimension and direction of the card ports. In a previous work we proposed the 3D Twin (3DT) torus which uses two 4-port cards per node, and obtained the optimal port configuration. This paper extends and generalizes that work in order to obtain the optimal port confi…
Initial Preparation and Characterization of Single Step Fabricated Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFC)
2013
In this study, facile tape casting process has been successfully carried out to fabricate an unit anode supported intermediate temperature solid oxide fuel cell (IT-SOFC) with four different layers: a composite cathode which is a mix of La0.6Sr0.4Co0.2Fe0.8O3 (LSCF48) and Gd0.1Ce0.9O1.9 (GDC10), GDC10 as thin electrolyte layer, NiO-GDC10 without pore former as thin anode functional layer (AFL), and anode support layer of NiO-GDC10 with carbon pore former. The multi-layer was sintered once to produce an unit planar cell. An OCV of 1.002 V at 500 °C, and maximum power density of 466 mW cm–2 at 648 °C are obtained. These results indicate negligible leakage of fuel through electrolyte. Furtherm…
A Teaching Laboratory in Analog Electronics: Changes to Address the Bologna Requirements
2008
Training new electronics engineers presents several major challenges. This paper proposes a new approach for practical lessons in second-level analog electronics, where students get a closer view of real-world practices in electronic engineering. The authors describe and evaluate a more dynamic way of teaching practical lessons in analog electronics in the first year of an electronic engineering degree. The method consists of creating a virtual company that contracts students to develop prototypes. The design process involves theoretical concepts from the students' lessons, and poses challenges with respect to costs and teamwork. The method brings the students closer to the working environm…
Layout influence on microwave performance of graphene field effect transistors
2018
The authors report on an in-depth statistical and parametrical investigation on the microwave performance of graphene FETs on sapphire substrate. The devices differ for the gate-drain/source distance and for the gate length, having kept instead the gate width constant. Microwave S -parameters have been measured for the different devices. Their results demonstrate that the cut-off frequency does not monotonically increase with the scaling of the device geometry and that it exists an optimal region in the gate-drain/source and gate-length space which maximises the microwave performance.
Graphene Field-Effect Transistors Employing Different Thin Oxide Films: A Comparative Study
2019
In this work, we report on a comparison among graphene field-effect transistors (GFETs) employing different dielectrics as gate layers to evaluate their microwave response. In particular, aluminum oxide (Al$_{2}$O$_{3}$), titanium oxide (TiO$_{2}$), and hafnium oxide (HfO$_{2}$) have been tested. GFETs have been fabricated on a single chip and a statistical analysis has been performed on a set of 24 devices for each type of oxide. Direct current and microwave measurements have been carried out on such GFETs and short circuit current gain and maximum available gain have been chosen as quality factors to evaluate their microwave performance. Our results show that all of the devices belonging …
Terahertz electrical writing speed in an antiferromagnetic memory
2018
The speed of writing of state-of-the-art ferromagnetic memories is physically limited by an intrinsic gigahertz threshold. Recently, realization of memory devices based on antiferromagnets, in which spin directions periodically alternate from one atomic lattice site to the next has moved research in an alternative direction. We experimentally demonstrate at room temperature that the speed of reversible electrical writing in a memory device can be scaled up to terahertz using an antiferromagnet. A current-induced spin-torque mechanism is responsible for the switching in our memory devices throughout the 12-order-of-magnitude range of writing speeds from hertz to terahertz. Our work opens the…
Comprehensive Modeling and Experimental Testing of Fault Detection and Management of a Nonredundant Fault-Tolerant VSI
2015
This paper presents an investigation and a comprehensive analysis on fault operations in a conventional three-phase voltage source inverter. After an introductory section dealing with power converter reliability and fault analysis issues in power electronics, a generalized switching function accounting for both healthy and faulty conditions and an easy and feasible method to embed fault diagnosis and reconfiguration within the control algorithm are introduced. The proposed system has simple and compact implementation. Experimental results operating both at open- and closed-loop current control, obtained using a test bench realized using a dSPACE system and the fault-tolerant inverter protot…
Thermal Analysis of the Solar Orbiter PHI Electronics Unit
2020
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High precision quantum query algorithm for computing AND-based boolean functions
2010
Quantum algorithms can be analyzed in a query model to compute Boolean functions. Function input is provided in a black box, and the aim is to compute the function value using as few queries to the black box as possible. The complexity of the algorithm is measured by the number of queries on the worst-case input. In this paper we consider computing AND Boolean function. First, we present a quantum algorithm for AND of two bits. Our algorithm uses one quantum query and correct result is obtained with a probability p=4/5, that improves previous results. The main result is generalization of our approach to design efficient quantum algorithms for computing composite function AND(f1,f2) where fi…