Search results for "Capacitor"
showing 10 items of 164 documents
Electrochemically Controlled Ion Dynamics in Porphyrin Nanostructures
2020
peer-reviewed The full text of this article will not be available in ULIR until the embargo expires on the 22/07/2021 The dynamics of ion intercalation into solid matrices influences the performance of key components in most energy storage devices (Li-ion batteries, supercapacitors, fuel cells, etc.). Electrochemical methods provide key information on the thermodynamics and kinetics of these ion-transfer processes but are restricted to matrices supported on electronically conductive substrates. In this article, the electrified liquid|liquid interface is introduced as an ideal platform to probe the thermodynamics and kinetics of reversible ion intercalation with nonelectronically active matr…
Photoswitchable Micro-Supercapacitor Based on a Diarylethene-Graphene Composite Film
2017
Stimuli-responsive micro-supercapacitors (MSCs) controlled by external stimuli can enable a wide range of applications for future on-chip energy storage. Here, we report on a photoswitchable MSC based on a diarylethene-graphene composite film. The microdevice delivers an outstanding and reversible capacitance modulation of up to 20%, demonstrating a prototype photoswitchable MSC. Terahertz spectroscopy indicates that the photoswitching of the capacitance is enabled by the reversible tuning of interfacial charge injection into diarylethene molecular orbitals, as a consequence of charge transfer at the diarylethene-graphene interface upon light modulation.
Microbeam SEE Analysis of MIM Capacitors for GaN Amplifiers
2018
Broad-beam and microbeam single-event effect tests were performed on metal–insulator–metal capacitors with three different thicknesses of silicon nitride (Si3N4) dielectric insulator: 250, 500, and 750 nm. The broad-beam tests indicated that the devices with the thicker, 500- and 750-nm dielectric did not have a greater breakdown voltage. The surrounding structures of the capacitor were suspected to be a possible cause. Microbeam techniques made it possible to localize the failure location for the 500- and 750-nm devices. The failure occurs in the air bridge structure connected to the top capacitor plate, which can therefore be considered as an edge effect, while for the 250-nm devices, the…
Radiation tolerance of NROM embedded products
2010
Radiation tolerance of NROM memories is demonstrated at the level of industrial 4 Mbit memory embedded modules, specifically not designed for operation in radiation harsh environments. The memory fabricated in 0.18 um technology remains fully functional after total ionization doses exceeding 100 krad. The tests were performed by irradiating with γ-rays (60Co source) and 10 MeV 11B ions in active (during programming/erase and read-out) and passive (no bias) modes. Comprehensive statistics were obtained by using large memory arrays and comparison of the data with the parameters of irradiated single cells allowed deep understanding of the physical phenomena in the irradiated NROM devices for b…
Statistical Analysis of Heavy-Ion Induced Gate Rupture in Power MOSFETs—Methodology for Radiation Hardness Assurance
2012
A methodology for power MOSFET radiation hardness assurance is proposed. It is based on the statistical analysis of destructive events, such as gate oxide rupture. Examples of failure rate calculations are performed.
Computer Aided Optimal Design of High Power Density EMI Filters
2016
Power density of power converter systems is becoming an increasingly stringent design constraint for a wide range of applications. Size reduction of EMI filter in power converters is an important aspect due to its significant impact on the overall converter volume and weight. In order to take on this issue, a computer aided procedure for a fast selection of optimal discrete EMI filter components and configuration is described in this paper. The proposed technique is a rule-based automatic procedure based on suitable databases that consider datasheets information of commercially available passive components (e.g. magnetic cores, capacitors). It allows the minimization of the filter's volume …
Crowded comparison operators for constraints handling in NSGA-II for optimal design of the compensation system in electrical distribution networks
2006
This paper proposes an improvement of an efficient multiobjective optimization algorithm, Non-dominated Sorting Genetic Algorithm II, NSGA-II, that has been here applied to solve the problem of optimal capacitors placement in distribution systems. The studied improvement involves the Crowded Comparison Operator and modifies it in order to handle several constraints. The problem of optimal location and sizing of capacitor banks for losses reduction and voltage profile flattening in medium voltage (MV) automated distribution systems is a difficult combinatorial constrained optimization problem which is deeply studied in literature. In this paper, the efficiency of the proposed Crowded Compari…
Application of circuit theory for extraction of water from oil
2011
This paper discusses optimization of the performance of a pulsed dc electrostatic coalescer, a device that is used in the oil industry to increase the speed of separation of water from a water-in-oil emulsion. A previously found criterion for optimum performance, the charge hypothesis, is reviewed. Analysis by circuit theory shows that the performance may be improved through selecting an optimum switching frequency and duty ratio, improving the design of the pulse train generator, and making physical modifications to the coalescer apparatus. The addition of an external charging circuit is beneficial. Experiments on the modified system could contribute to a better understanding of the physic…
Optimal Integration of Hybrid Supercapacitor and IPT System for a Free-Catenary Tramway
2019
The aim of the paper is the study of an optimal integration of a supercapacitor-based storage system and inductive power transfer system for the free-catenary operation of a tramway. Starting from the definition of the topology of inductive power transfer system, we propose and analyze a design procedure for the pads of the inductive power system. In the second part of the paper, an optimal integration strategy for the correct size of on-board supercapacitors and the power of the inductive energy transfer are proposed. The results obtained by means of numerical simulations are discussed. © 2018 IEEE.
Hybrid magnetic materials based on layered double hydroxides: from the chemistry towards the applications
2014
Layered double hydroxides (LDHs) are the leitmotiv of this dissertation. Contradicting the assertion that “any past was better”, LDHs have been continuously revisited from the middle of the twentieth century, and represent an excellent example of the never-ending beauty of Chemistry. New synthetic perspectives are giving a new impetus to LDH chemistry, which among hybrid materials, are finding their heyday. This is resulting in novel materials and also paving the way for new fundamental and practical insights. This dissertation is focused on magnetic LDHs, and for the sake of clarity it is organized in three main parts: we will move from basic synthetic and physical aspects of LDHs, through…