Voltage and current measurements of a laser preionization triggered spark gap switch (50 kV, 18 kA, 100 nsec} reveal a voltage drop across the gap of several kilovolts during the current plateau for a variety of gas mixtures. This voltage drop is much larger than what is generally believed to exist in a spark gap switch during the conduction phase. The reasons for the large voltage drop are exp...

In this paper, local spark sintering of a ceramic-metal system (SiO₂-Sn) during microwave processing was examinedby means of synchrotron-radiation-computed tomography technology. From the reconstructed 3-D and cross-section images of the specimen, adensification process was observed below the melting point of Sn, and then the specimen came into a rapid densification stage. These results may be ...

Genomic sequencing typically generates a large collection of unordered contigs or scaffolds. Contig ordering (also known as gap closure) is a non-trivial algorithmic and experimental problem since even relatively simple-to-assemble bacterial genomes typically result in large set of contigs. Neighboring contigs maybe separated either by gaps in read coverage or by repeats. In the later case we s...

Interesting, “new”, very high peak-power pulsed radio frequency (RF) antennas have been assembled at the HIPAS Observatory (Alaska, USA) and also at the University of California at Los Angeles (UCLA, USA); namely, a pair of quarter wavelength (λ/4) long cylindrical conductors separated by a high voltage spark gap. Such a combination can radiate multi-megawatt RF pulses whenever the spark gap fi...

Stem-cell research. Euthanasia. Personhood. Marriage equality. School shootings. Gun control. Death penalty. Ethical dilemmas regularly spark fierce debate about the underlying moral fabric of societies. How do we prepare today's children to be fully informed and thoughtful citizens, capable of moral and ethical decisions? Current approaches to moral education are controversial, requiring adult...

A supercritical (SC) nitrogen (N2) switch is designed and tested. The dielectric strength and recovery rate of the SC switch are investigated by experiments. In order to theoretically study the discharge and recovery process of the SC N2 switch under high repetition rate operation, a numerical model is developed. For SC N2 with initial parameters of p = 80.9 bar and T = 300 K, the simulation re...

Design and implementation of a 10kV subnanosecond pulse generator using Trigatron type spark gap as a switch. Straightforward and compact trigger generator using pulse shaping network which produces a trigger pulse of subnanosecond rise time. A pulse power system requires delivering a high voltage, high coulomb in short rise time. This is achieved by using pulse shaping network comprises of par...

In this paper, fuzzy logic integrated with the Taguchi method is used to optimize Wire Electro Discharge Machining (WEDM) process with multiple quality characteristics. Rough machining with EDM gives poor surface finish and has micro cracks and pores. Finish machining gives better surface finish but with very poor machining speed (MRR). Spark gap width is one of the important performance measur...