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A testing procedure has been developed with the aim to investigate and to screen the current interruption capability of vacuum interrupters with different contact materials. A synthetic circuit delivering a 1.2ms pulse current up to 18 kA was used in order to simulate a surface temperature on the electrodes similar to the constricted arc mode. At current zero a pulse voltage was injected to stress...
Field electron emission is recognized as one of important phenomena related to the occurrence of electrical breakdown in vacuum. In this paper, we investigated the distribution of field electron emission sites on a plane electrode before and after current conditioning procedure. The investigation was carried out by scanning the electrode to measure the emission current flowing through the pin-hole...
Surface discharges at the solar array on the spacecrafts are originated from electrification. Now, estimation of the electrical potential of the spacecraft by electrification is carried out. But, the reliability of the calculated results depends on the accuracy of the physical properties. One of the desired property is the secondary electron emission coefficient (SEEC): δ (The number of secondary...
A vacuum arc voltage of rising up like a step establishes transient oscillating currents in a closed circuit with a parallel capacitor and an inductance. From previous investigation, we found that a current zero was realized by the transient oscillating current caused by the transient phenomena or the instability phenomena. This paper presents detailed investigation results of the transient phenomena...
In order to clarify the characteristics of spark conditioning carried out in parallel at several parts of electrodes, we carried out conditioning experiment to use a multi-gap electrode system with multi-rod electrodes. As a result, we found that 50% breakdown voltage after conditioning saturation differed in the multi-gap electrode system from in a single gap electrode system. In addition, we found...
Supercapacitors have been focused for their great capacitance, fast charging-discharging with big current, and very long cycle life since they were born. In recent years, with their applications in national security science technology, environmental reservation and so on, the studies on them have become one of the hot spots in the strategic field. This paper presents a preparation that KMnO4 and Na...
The possibility is shown to synthesize a nanodispersed powder in the system “carbon-nitrogen” in a hypervelocity electrical discharge plasma jet generated by a coaxial magnetoplasma accelerator (CMPA). The plasma shot is provided in the pressurized chamber filled with the gaseous nitrogen. Up to 1 gram of black powdered product is synthesized for one working cycle having a duration about 100 ms. According...
In this thesis, electrochemical corrosion and electrochemical migration characteristics of 64Sn-35Bi-1Ag (SBA) solder with In doping in 3wt.% NaCl solution are researched by potentiodynamic polarization measurement and a self-designed experiment, respectively. The surface morphology and elemental composition of corrosive products and dendrites during ECM process are determined by SEM, EDAX techniques...
This paper is to the assembly and fabrication for typical nano device-SWCNT FET for example, facing the large-scale assembly and fabrication for nano devices, and carrying out the experimenal research. Assembly method of SWCNTs FET is by floating potential and dielectrophoresis principle. Six hundred devices were assembled less than per square centimeter. The experimental results showed that large-scale...
Electronic noses (e-nose) have been studied for several years and extensively applied; however, they are limited by their volume and high manufacturing cost. Portable devices have become popular in recent years; therefore, it is crucial to integrate e-noses in portable devices (e.g., mobile phones). This study used TSMC 90nm 1P9M CMOS MSG technology to develop a front-end system-on-chip (SoC) for...
A hybrid X-pinch configuration consisting of solid conical electrodes connected by a wire was first tested on the 45 ns rise time, 500 kA peak current XP pulsed power generator1. In more recent work the hybrid X-pinch was studied on generators with peak currents from 250 kA to 1.2 MA and current rise time from 45 ns to 170 ns. In all experiments the hybrid pinches have the same 60° conical electrodes...
Electron hop funnels have been constructed of Low Temperature Co-fired Ceramic (LTCC) to enhance the performance of gated field emitter arrays (FEAs). Electrons are emitted into the wide end of the funnel, transmitted through the funnel, and exit through the narrow opening. An electrode, referred to here as the hop electrode, is placed around the narrow end of the funnel to create the electric field...
Accumulation of space charge within a polymeric dielectric material, especially under dc voltage, is associated with its degradation. Space charge accumulation modifies the local field within the material and might contribute to its aging. Further, it would modify the conduction through the material. Formation of space charge within the dielectric material depends on the charge injection from metal-dielectric...
One lidless CPU product failed more than 20% of visual inspections due to foreign material near the capacitor electrodes during testing production. This paper presents the analysis method for the foreign material, formation mechanism of dendrites, verification experiment by DOE, root cause for this case, and corrective solutions.
Electrical Capacitance Tomography (ECT) is a method to determine the material distribution within the interior of a closed object by measuring the capacitance values across externally mounted electrodes. Traditionally, an AC excitation pulse is applied to a pair of electrodes that form a capacitor during each measurement step, in order to determine the capacitance from the output current measured...
(The gas metal arc welding (GMAW) process is widely used due to its universal applicability, high deposition rate and automatic feeding of the filler material. However, in order to perform process optimization and further develop this welding technique a better understanding of the complex physical and chemical transactions is required. More thorough investigation is needed, in particular to describe...
Particle growth has been a subject to many different investigations. Besides industrial interests also the fundamental processes are being studied. It has been found, that particle growth can be divided into three stages: nucleation, coagulation and accretion [1].
This paper reports a comparison studies between two erosion rate model and experimental results of an Electrical Discharge Machining (EDM) process for high gap current. Two erosion rate models are Dimensional Analysis (DA) model and Artificial Neural Network (ANN) model that have been summarized from the previous author's publication. The data analysis is based on a copper electrode and steel workpiece...
We propose the feasibility of bidirectional selection device characteristics in ultrathin (<3nm) TiO2 layer. We utilized the localized conducting path as virtual electrode to investigate device property at extremely scaled area. By using electrical method such as “forming” and “reset” processes in oxide, virtual electrode/sub-3nm-thick TiO2/virtual electrode structure was achieved. The measured...
This presentation describes the teaching experience in a course on Sensors Electronics following the criteria of the Erasmus Mundus Masters and applied to International Master in Materials and Sensor Systems for Environmental Technologies given at Universitat Politècnica de Valencia. The main teaching challenge was to provide a course of clearly electronic content to students from any related field,...
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