Recent advances in pulsed electron gun technology have resulted in femtosecond electron pulses becoming available for ultrafast electron diffraction experiments. For experiments investigating chemical dynamics in the gas phase, the resolution is still limited to picosecond time scales due to the velocity mismatch between laser and electron pulses. Tilted laser pulses can be used for velocity ma...

The aim of this study is to perform a simulation study of the thermal and mechanical effects of a flat rectangular (3 × 10 mm), MRI compatible transducer operating at 5 MHz for the purpose of destroying atherosclerotic plaque. The simulation study focuses on measuring the plaque destruction (due to the thermal of mechanical mode of ultrasound) as a function of power, time, frequency, duty facto...

Triangulation and histological studies were made of skin ablation depths following skin treatments with a Fotona Dynamis Er:YAG laser system. The following laser handpieces were used in the study: Full beam handpieces R04 and R11; Stamping patterned handpieces PS01, PS02 and PS03; fractionated handpiece FS01 and c) Scanning fractional handpiece F22. The laser fluence (F) was found to be the maj...

Pulsed laser machining offers many unique capabilities that continuous-wave (CW) laser machining cannot. In pulsed laser machining, however, the additional process parameters of peak power, pulse frequency and pulse duration make it more difficult to find and fine tune a suitable operation window. This becomes harder in micromachining applications where tolerance of inaccuracy is smaller. How t...

To study the influence of crash pulse duration on injury risk, data of 272 real life frontal collisions with recorded crash pulses was used. 371 restrained occupants were included. It was found that compared with acceleration, the duration has a limited influence on injury risk. The study shows that the average pulse duration in cases with AIS2+ injuries was 7 % longer than in cases with AIS1 i...

When clusters of deuterium are irradiated with an intense, ultrafast laser pulse, the clusters explode, generating ions with kinetic energies high enough to produce nuclear-fusion events. Here we present experimental measurements of the dependence of the fusion yield of an exploding deuterium-cluster plasma on pulse energy up to the 10-J level for incident pulse durations of 100 fs and 1 ps. Th...

This research investigated the ability of subjects to detect small haptic effects, and the associated gains in task performance with various configurations of haptic stimulus. Variations in amplitude, shape, and pulse duration were studied. An adaptive thresholding method was used to obtain detection thresholds for actively explored haptic icons ranging in size from 3 to 5 mm, smooth vs rough a...

Frequency-chirped free-electron lasers (FELs) are useful to generate a large photon bandwidth or a shorter xray pulse duration. In this paper, we present a threedimensional analysis of a high-gain FEL driven by the energy-chirped electron beam. We show that the FEL eigenmode equation is the same for a frequency-chirped FEL as for an undulator-tapered FEL. We study the transverse effects of such...

AbsfracfThis paper presents the results of average and impulsive noise measurements inside several office buildings and retail stores. The noise measurement system operated at 918 MHz, 2.44 GHz, and 4 GHz with a nominal 40 MHz 3 dB RF bandwidth. Omnidirectional and directional antennas were used to investigate the characteristics and sources of RF noise in indoor channels. Statistical analyses ...

Soft x-ray emission from plasmas produced by ablation from a magnesium target employing a ruby laser is studied using a grazing incidence spectrograph in the spectral region 3–12 nm. Emission intensities are investigated for different ionic lines as a function of position, time after the maximum of the laser pulse and laser irradiance. A gated pinhole camera is employed for studying the evoluti...