Search results for " Capacitor"
showing 5 items of 25 documents
CFRP STRUCTURAL CAPACITORS: EFFECT OF DAMAGE AND MECHANICAL LOAD ON CAPACITANCE
2013
Aim of this work is to study the effect of mechanical load and damages, on the performance of structural capacitors, made by CFRP composite laminates with a PET dielectric film (treated with sodium hydroxide) inserted at the laminate middle-plane. Such capacitors have been characterized by ILSS and tensile tests and the properties so estimated were compared to those of the simple CFRP. By measuring the capacitance before mechanical loading, under loading and after unloading, it has been observed that, due to the damage of the CFRP layers, proved also by proper fractographic analysis, at high strain level the capacitance decreases although it exhibits a complete recovery after unloading. Suc…
The Effect of Anodizing Bath Composition on the Electronic Properties of Anodic Ta-Nb Mixed Oxides
2022
Anodic oxides were grown to 50 V on Ta-Nb sputtering deposited alloys, with high Nb content, in acetate ions containing an aqueous solution to study the effect of the anodizing bath composition on anodic layers’ dielectric properties. Photoelectrochemical measurements proved the presence of a photocurrent in the band gap of photon energy lower than oxides, due to optical transitions involving localized electronic states as a consequence of acetate ions incorporation. Flat band potential value estimates assessed the insulating nature of the anodic oxides grown in the acetate buffer solution. Differential capacitance measurements showed that the highest capacitance value was measured for the …
Physico-chemical Characterization of Aluminium Oxide Films Grown on Etched Foils for Electrolytic Capacitors
2012
Polymer Selection and Cell Design for Electric-Vehicle Supercapacitors
2000
Supercapacitors are devices for applications requiring high operating power levels, such as secondary power sources in electric vehicles (EVs) to provide peak power for acceleration and hill climbing. While electronically conducting polymers yield different redox supercapacitor configurations, devices with the n-doped polymer as the negative electrode and the p-doped polymer as the positive one are the most promising for EV applications. Indeed, this type of supercapacitor has a high operating potential, is able to deliver all the doping charge and, when charged, has both electrodes in the conducting (p- and n-doped) states. This study reports selection criteria for polymer materials and ce…
Some Aspects of the Influence of Particle Size on Properties and Behaviour of a Dielectric Material : Example of Barium Titanate
1989
Anybody agrees with the idea that particle size plays an important role in the behaviour of a polycrystalline material but very few studies are giving precise information about this role. In this paper some experimental results are presented succintly to illustrate the importance of this physico-chemical factor. They are related to barium titanate, the main component of the dielectric material in the type II ceramic capacitors.