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A laboratory ultrasound technique has been developed to measure the longitudinal velocity of sound in high purity and density boron carbide and lanthanum hexaboride materials prepared by shock wave compression. Using the measured value of the longitudinal velocity of sound υ_L, we have calculated the Young's modulus E, the Bulk modulus K, the Shear modulus G and the Poisson's ratio ν. X-rays diffraction has also been carried out on these materials.

The aim of this work is to examine the influence of the type and concentration of an electrolyte solution on the optical characteristics of CdS nanoparticles produced by the sonochemical approach. The optical characteristics of the samples were examined using an Ultraviolet–Visible (UV–Vis) spectrophotometer in order to calculate the bandgap value. Acquired samples were examined on how to change the bandgap at various concentrations within various electrolyte solutions in order to ascertain the effects of various ambiences. Cadmium nitrate tetrahydrate (Cd (NO${}_3{)}_2\cdot$4H₂O), cadmium acetate dihydrate (Cd(CH₃COO)${}_2\cdot$2H₂O) and sodium chloride (NaCl) water solutions were utilized as electrolytes in three different environments. When the sample was exposed to a different environment, its energy spectrum changed. Measurements show that raising the concentration of various electrolyte solutions decreased the bandgap values of the samples.

Periodicity (in time or space) is a part and parcel of every living being: one can see, hear and feel it. Everyday examples are locomotion, respiration and heart beat. The reinforced N-dimensional periodicity over two or more crystalline solids results in the so-called phononic band gap crystals. These can have dramatic consequences on the propagation of phonons, vibrations and sound. The fundamental physics of cleverly fabricated phononic crystals can offer a systematic route to realize the Anderson localization of sound and vibrations. As to the applications, the phononic crystals are envisaged to find ways in the architecture, acoustic waveguides, designing transducers, elastic/acoustic filters, noise control, ultrasonics, medical imaging and acoustic cloaking, to mention a few. This review focuses on the brief sketch of the progress made in the field that seems to have prospered even more than was originally imagined in the early nineties.

The majority of ultrasonic characterizations are done on thermoplastics, with just a few articles available on the characterization of thermoset resin characteristics. A non-destructive methodology for monitoring fatigue and static deformation induced by mechanical loading on a fiber-reinforced plastic is presented. However, these materials’ dynamics of elastic waves are considerably more complicated. A large part was devoted to the calculation of dispersion curves of guided waves in composites. Therefore, this study presents a thorough description of the Glass/Epoxy system by comparing ultrasonic and mechanical data. Ultrasonic wave propagation at high frequencies, functioning as a dynamic mechanical deformation, may be utilized to calculate longitudinal and shear moduli during static and dynamic loading. The evolution of attenuation and velocity during loading is linked to the significant changes that occur during the aging process. The experimental transfer function is determined by the Fourier transform of all the obtained ultrasonic echoes.