Most vacuum devices are hampered by ion bombardment due to residual gases. Sometimes, it causes the breakdown of devices and shortens their life. In this article, the effect of the ion bombardment on the cathode surface in a structure of a field emission display was simulated. In this structure, a special type of spacer was used, named “hop” and “flu” spacer. The trajectories of electrons emitt...

this study presents the electric behavior of sandwich devices based on porous silicon (ps) thin films with au/ps/si/cu structure when the material’s surface is exposed to different gases. ps thin films were fabricated by the electrochemical anodization method of si–c (100) substrates with resistivity 1.4-2.6 ωcm. samples were anodized in a solution of hf (48%), c2h5oh (99.98%) and distilled wat...

Dissolved gas analysis (DGA) is a reliable technique for detecting the presence of incipient fault conditions in oil immersed transformers. In this method the presence of certain key gases is monitored. The various analysis methods are : Rogers ratio, IEC ratio, Doernenburg, Duval triangle, key gas, artificial neural network (ANN) method. In this paper the various DGA methods are evaluated and ...

SF6 is a gas with excellent dielectric properties and is commonly used in gas-insulated equipment. However it has the high global warming potential. Thus, the development of new gases or gas mixtures for GIS, GIL is strongly desired. For dimensioning the gas insulated systems the support insulators (spacers) are of special interest. Contaminations on the insulator surface can cause field distor...

The impact of pulsed electric fields (PEF) on cellular integrity and texture of Ranchero and Sabroso onions (Allium cepa L.) was investigated. Electrical properties, ion leakage rate, texture, and amount of enzymatically formed pyruvate were measured before and after PEF treatment for a range of applied field strengths and number of pulses. Critical electric field strengths or thresholds (E(c))...

The evolution of negative streamers during electric breakdown of a non-attaching gas can be described by a two-fluid model for electrons and positive ions. It consists of continuity equations for the charged particles including drift, diffusion and reaction in the local electric field, coupled to the Poisson equation for the electric potential. The model generates field enhancement and steep pr...

[1] Previous research has shown that the statistical measurements of charge moment changes in sprite-producing lightning are in general agreement with the predictions based on the conventional breakdown theory for sprite initiation in the mesosphere. Measurements have progressed to the point where a detailed, event-level quantitative comparison between the measurements and predictions could mor...