The Resonalyser method uses resonance frequencies measured on rectangular plate specimens to identify orthotropic material properties. An inverse technique is used to update the material properties in a numerical model of the test plate. The obtained material properties of steel and aluminum test plates are validated with the results of standard impulse excitation tests and standard tensile tes...

An impact source identification technique for finite isotropic plates using a time-reversal method with associated signal processing algorithms is investigated experimentally. A series of low velocity impact experiments on an aluminum plate is performed to verify this impact identification method using merely four piezoelectric sensors. Validation of the experimental system for impact source id...

HEPA Filter Critical Flow Orifice A personal, thermophoretic particle sampler was designed to collect airborne nanoparticles in the breathing zone of exposed workers. The thermal precipitator captures aerosol by creating a 1000 ̊C/cm temperature gradient between two aluminum plates (0.1 cm separation distance) using a resistive heater, a thermoelectric cooler, a temperature controller, and two t...

In the present study, dispersion and displacement curves of ultrasonic lamb wave, propagated in Aluminum thin plates, were drawn. Two ultrasonic lamb wave techniques, pulse-echo (a1 mode as emitter) and emission (s1 mode as emitter), were used for interpretation of notch defects with depths of 10%, 30% and 60% of plate thickness. Thickness of plate was 2 mm and the nominal centre frequency of t...

A comprehensive methodology that takes into account alloy solidification, shrinkage-driven interdendritic fluid flow, hydrogen precipitation, and porosity evolution has been developed for the prediction of microporosity fraction in aluminum A356 alloy castings. The mathematical models presented are implemented in a computational framework consistent with those of commercial casting codes, allow...

Fast remaining thickness measurement using Lamb wave is presented for the purpose of maintenance of large structures like oil storage tanks and pipe networks. This study used a laser ultrasonic source to perform a high resolution remote scanning over aluminum plates with grooved and circular defects that were modeled on corrosions in plate-like structures. The antisymmetric A0 and symmetric S0 ...

This brief note reports on a study that applies the reassigned spectrogram (the reassigned energy density spectrum of the short-time Fourier transform [STFT]) to develop the dispersion curves for multimode Lamb waves propagating in an aluminum plate. The proposed procedure first uses the spectrogram to operate on a single, laser-generated and detected waveform to develop the dispersion relation...

We observe oblique impacts of a hard aluminum oxide sphere on a thick elastoplastic polycarbonate plate by recording stroboscopic photographs of the sphere trajectory and spin. The apparent kinematic coefficient of normal restitution grows monotonically with the magnitude of the tangent of the angle of incidence, and the apparent coefficient of friction decreases with increasing normal impact v...

Metal-liquid interfaces are of the utmost importance in a number of scientific areas, including electrochemistry and catalysis. However, complicated analytical methods and sample preparation are usually required to study the interfacial phenomena. We propose an infrared spectroscopic approach that enables investigating the molecular interactions at the interface, but needing only minimal or no ...

A numerical study is made of transient heat and mass transfer in metal hydride beds in the hydriding process with the addition of internal aluminum plates. The two-dimensional equations governing the hydration kinetics, hydrogen ̄ow and heat transfer are solved by using the iterative method based on the ®nite-volume technique. It is found that the heat transfer is enhanced by the installation o...