An experimental demonstration of the broadband passive damping capacity a vibro-impact acoustic black hole (VI-ABH) is reported. A VI-ABH an adaptation classical ABH design consisting beam with tapered edge decreasing thickness creating (ABH), complemented by contact points on which impacts during its vibration. The nonlinearity creates rapid and efficient transfer vibrational energy from low-f...

In this paper, a high peak/average power picosecond pulsed master‑oscillator power‑amplifier (MOPA) system utilizing tapered large mode area double-clad fiber (T-DCF) is presented. average regime, we report MOPA laser with up to 613 W at 20 MHz repetition rate 50 ps pulse duration (613 kW of peak and 30.6 μJ energy). over 3MW pulses (at seed source bandwidth) 1 (310 energy 310 average) was demo...

The FIB Instrument The basic functions of the FIB, namely, imaging and sputtering with an ion beam, require a highly focused beam. A consistent tenet of any focused beam is that the smaller the effective source size, the more current that can be focused to a point. Unlike the broad ion beams generated from plasma sources, high-resolution ion beams are defined by the use of a field ionization so...

Phased array antennas afford many advantages over traditional reflector antennas due to their conformality, high aperture efficiency, and unfettered beam steering capability at the price of increased cost and complexity. This paper eliminates the complex and costly array backend via the implementation of a series fed array employing a propagation constant reconfigurable transmission line connec...

The aim of this in vitro study was to determine whether irrigation with apical negative pressure was more effective than traditional positive-pressure irrigation in eradicating Enterococcus faecalis from preshaped root canals. Fifty-four extracted mandibular molars were instrumented to produce either a non-tapered or tapered preparation, sterilized, inoculated with E. faecalis for 30 days, and ...

Helix travelling-wave tubes (TWTs) are extensively employed as final power amplifiers in satellites. These applications demand low spectral noise and high efficiency across a broad band. Research has been carried out to achieve these criteria in a helix TWT design. A deeper understanding has been gained on how the basic parameters of a TWT affect its non-linear performance. By selecting and con...

This article presents a method used to guide the beam from an argon fluoride excimer laser to make it suitable for microsurgical purposes and confine it to areas that can be varied in dimension from 1 micron to tens or hundreds of microns. This approach guides the excimer laser beam with an articulated mechanical arm and confines it with variable-diameter tapered tubes, possibly allowing the us...

PEP-II, the SLAC, LBNL, LLNL B-factory has achieved a peak luminosity of over 9×10 cms, more than 3 times the design luminosity, and plans to obtain a luminosity of over 1×10 cm sec in the next year. In order to push the luminosity performance of PEP-II to even higher levels an upgrade to the interaction region (IR) is being designed. In the present design, the interaction point (IP) is a head-...