In this paper the influence of non-acoustic properties on the sound absorption coefficient of polyurethane foams as a porous medium is investigated. Biot’s equations with transfer matrix method, as the solution approach are employed to evaluate the sound absorption coefficient of selected polyurethane foams. The major issue is the dependency of non-acoustic properties on each other which makes ...

4.1 Acoustic Microscopy Theory, Techniques, and Specimen Preparation The Physical Interaction between Ultrasound and Solid Media • A Historical Perspective of the Study of Bone with Acoustic Microscopy • Specimen Preparation • The Acoustic Microscope 4.2 Acoustic Studies of Cortical Bone Material Properties Low Frequency • High Frequency 4.3 Acoustic Microscopy and Biomaterials Analysis Acousti...

the course of consecutive experiments in this report aimed to a research or introductory identification about mechanical and acoustical properties of maple (acer velutinum) wood. studied factors were included quality factor (due to internal friction), acoustic coefficient, acoustical conversion efficiency as well as the modulus of elasticity (young’s modulus) which they were all accomplished us...

Carbon / epoxy composite is one of the most useful polymer matrix composites that has special properties such as high strength-to-weight ratio, high hardness, high corrosion resistance, Resistance to nuclear radiation has high consumption in different industries such as aerospace industry. Therefor monitoring of loading of this type of composite is important. In order to determine failure mecha...