Lasers can be used to excite and detect ultrasonic waves in a wide variety of materials. This allows the measurement of absolute particle motion without the mechanical disturbances of contacting transducers. In an ultrasound transmission experiment, the wave field is usually accessible only on the boundaries of a sample. Using optical methods, one can measure the surface wave field, in effect, ...

High-density polyethylene (HDPE) piping has been used in place of steel alloys in the petrochemical, power, and mining industries due to its exceptional resistance to corrosion and erosion. Recently, HDPE has also been used for nuclear safety-related cooling water applications. The application of nuclear quality assurance requirements creates reasonable assurance that the production fusion join...

In many industrial applications through transmission ultrasonic measurements are widely used because they enable to perform characterization and long term monitoring of material properties. The waveform of the signal transmitted through the plastic object usually is distorted due to different factors, such as frequency dependent attenuation, phase velocity dispersion, diffraction, geometry of b...

NiMoO(4) nanorods have been successfully synthesized by sonochemical method process by using Ni(CH(3)COO)(2) · 4H(2)O and (NH(4))(6)Mo(7)O(24) · 4H(2)O as starting materials. Some parameters including ultrasonic power, ultrasonic irradiation time, stirring effect, solvent effect, and surfactant effect were investigated to reach optimum condition. The as synthesized nanostructures were character...

Nanoscale hydroxyapatite based ceramics are a relatively new form of materials that are currently being investigated for a number of potential biomedical applications. This study reports on a straightforward wet chemical method that uses calcium hydroxide and phosphoric acid as precursors. After chemical synthesis a conventional thermal treatment was used to produce an ultrafine hydroxyapatite ...

In this study, the synthesis of Mn(3)O(4) (husmannite) nanoparticles was carried out in two different alkali media under sonication by ultrasonic bath and conventional method. Manganese acetate was used as precursor, sodium hydroxide and hexamethylenetetramine (HMT) as basic reagents in this synthesis. An ultrasonic bath with low intensity was used for the preparation of nanomaterials. The as p...

Quantitative ultrasonic methods were studied for characterizing skin lesions in vivo using contact dermatitis as an example. The parameters studied include skin thickness, echogenicity, attenuation coefficient slope and parameters related to echo statistics (signal-to-noise ratio and shape parameters of Weibull, K and generalized gamma distributions). Data were collected using a high-frequency ...

We proposed an approach to construct a 2D Fresnel lenses by acoustic network. This lens iscomposed of an array of Helmholtz resonators. The resonance at individual resonators results ineffective focusing even the plate has subwavelength thickness. The FEM simulation resultspresented the ultrasonic wave propagation through the lenses together with the resultingdiffraction pat...