In this paper, we introduce a C-scan ultrasound prototype and three imaging modalities for the detection of foreign objects inserted in porcine soft tissue. The object materials include bamboo, plastics, glass and aluminum alloys. The images of foreign objects were acquired using the C-scan ultrasound, a portable B-scan ultrasound, film-based radiography, and computerized radiography. The C-sca...

In the very near future gravitational wave astronomy is expected to become a reality, giving us a completely new tool for exploring the universe around us. We provide an introduction to how interferometric gravitational wave detectors work, suitable for students entering the field and teachers who wish to cover the subject matter in an advanced undergraduate or beginning graduate level course. ...

We specifically developed a diode-pumped, Q-switched Nd:YAG laser to act as a pump source for a terahertz-wave parametric generator. A single Q-switched laser pulse ~pulse width 12 ns, pulse repetition frequency 40 Hz! produced an output energy of 12 mJ. Utilizing this pump source, we were able to construct a compact ~6503350 mm! terahertz-wave parametric generator using LiNbO3 crystals. We ach...

One region of the electromagnetic spectrum that is relatively unexploited for materials characterization is the millimeter wave band frequencies roughly between 40 and 300 GHz . Millimeter wave techniques involve free-space noncontacting measurements which have a length scale that makes them ideal for characterizing bulk properties of multicomponent composites where the scale of homogeneity is ...

Electrostatic drift wave linear stability analysis is carried out for the Helimak configuration and compared against experimental data. Density fluctuation and cross-spectrum measurements show evidence of a coherent mode propagating perpendicular to the magnetic field which becomes unstable at k s 0.15. By comparing the experimental results with the wave characteristic of linear two-fluid theor...

Ion acoustic wave phenomena are studied and compared in two low-pressure argon discharges created by helicon sources. The wave amplitudes are spatially localized near the edge of a plasma column as the amplitudes of the “mirror waves” that are separated from the helicon source frequency by the ion wave frequency. Dependencies of the ion wave on radial position, pressure, input power, and magnet...

This paper examines in detail the characteristics of a leaky Lamb wave propagating in a piezoelectric plate immersed in a dielectric or conductive fluid. The analysis is based on the partial wave analysis and its numerical calculations. Some corrections have been made so that both the changes in phase velocity and the wave attenuation of leaky Lamb waves caused by fluid’s mechanical, dielectric...

We have developed an imaging method for locating isolated nonlinear scattering source~s! in solids. It relies on extracting the nonlinear response of a solid by modulation of a high by a low-frequency wave, and employing moving-window, synchronous detection. The resulting image consists of nonlinear wave reflection profiles with remarkable sensitivity to an isolated elastic nonlinear source~s!....

The frequency and direction dependence of transmission coefficients at interfaces was investigated theoretically. The interfaces are formed by having two Lennard-Jones materials differing in mass and interatomic potential equally divided at the center of an fcc lattice system. A single frequency wave-packet is generated at one end of the system and allowed to propagate through the system until ...