The transmission coefficient of a layered structure made of glass and water was calculated using transfer matrix method and also measured as a function of frequency. It was found that acoustic band gaps can be created using only 3–4 cells of a two-phase layered structure. By introducing two or more periods into the layered structure, very sharp passbands and very broad stopbands can be engineer...

Metamaterials have been the subject of significant interest over the past decade due to their ability to produce novel acoustic behaviour beyond that seen in naturally occurring media. As well as their potential in acoustic cloaks and lenses, of particular interest is the appearance of band gaps which lead to very high levels of attenuation across the material within narrow frequency ranges. Un...

Phononic crystals (PCs) can exhibit phononic band gaps within which sound and vibrations at certain frequencies do not propagate. In fact, PCs with large band gaps are of great interest for many applications, such as transducers, elastic/acoustic filters, noise control, and vibration shields. Previous work in the field concentrated on PCs made of elastic isotropic materials; however, band gaps ...

The vibro-acoustic performance of a fluid-loaded periodic locally resonant (LR) plate was examined in this research, with specific focus on the effect water fluid vibration and sound radiation LR structure. analytical models plate’s band gap, vibration, acoustic were theoretically derived closed-form solutions, which can be used to predict general rules underwater results show that band-gap wid...

in this paper, undopedzno and co-znonano structureswith different molar ratio of cobalt have been synthesized by the sonochemical method. structure have been characterized by fourier transform (ftir) and uv–vis spectroscopy,scanning electron microscopy (sem), energy dispersive analytical x-ray (edax), and x-ray diffraction (xrd) methods. moreover, the direct band gap has been calculated by tauc...

in the present study, co-zno and co-ni-zno nanoparticles were synthesized by sonochemical methods and the structural and optical properties were investigated through fourier transform infrared spectroscopy (ftir), uv-vis spectroscopy, field emission scanning electron microscopy (fe-sem), x-ray diffraction (xrd), and photoluminescence spectroscopy (pl) methods. morphology of nanoparticles obtain...