Noise pollution remains a challenging problem requiring the development of novel systems for noise insulation. Extensive work in the field of acoustic metamaterials has led to various ventilated structures which, however, are usually demonstrated for rather narrow regions of the audible spectrum. In this work, the idea of metamaterial‐based systems is further extended, developing the concept of a metahouse chamber representing a ventilated structure for multiple band noise insulation. Broad stop‐bands originate from strong coupling between pairs of Helmholtz resonators constituting the structure. The averaged transmission −18.6 dB are demonstrated numerically and experimentally within the spectral range from 1500 to 16 500 Hz. The sparseness of the structure together with the possibility to use optically transparent materials suggest that the chamber may be also characterized by partial optical transparency depending on the mutual position of structural elements. The obtained results are promising for development of novel noise‐insulating structures advancing urban science.

In this work we investigate a periodic structure in the frequency range from 20 Hz to 5500 Hz designed for broadband noise insulation. The considered unit cell consists of a simple structure: a pair of polymer pipes with slits carved along the axes, representing two coupled Helmholtz resonators. In order to develop a design with a broad band gap, we analyze the eigenmodes of the infinite two-dimensional structure considering their symmetry and interaction. This analysis is supported by parametric optimization of the resonator geometry. The obtained band diagram is compared with numerically determined transmission coefficient of a finite structure based on the same unit cell. The number of unit cells of the finite structure is chosen to be sufficient for demonstration of insulating properties and stop band formation. Furthermore, we analyze how the transmission coefficient is linked to the pressure field distribution inside the resonators. Owing to the simplicity of the geometry, the obtained results may become a basis for development of budget-friendly passive systems for broadband noise insulation within the audible range of frequencies.

Scoliosis, being one of the most widespread spinal diseases among children, has been studied extensively throughout the history of medicine, yet there is no clear understanding of its initiating factors and the mechanogenesis of the monomorphic three-dimensional deformation due to its polyetiological nature. We present a novel mathematical model of the process of emergence of the three-dimensional deformation of the human spine based on variational principles. Typical scoliosis geometry is assumed to be described as minimal curves of a particular energy functional, which are shown to closely resemble actual scoliosis. We investigate the numerical properties of the first stage of scoliosis, which is shown to have the highest influence on the development of the disease.

Following the fundamental work by Bazaron, Bulgadaev and Derjaguin [6] on the observation of shear elasticity of low viscous liquids, we build on this study by examining viscous liquids, polymers and suspensions of nanoparticles. In this paper, we review our past and current efforts in these areas. The mechanical properties of liquids, polymers and nanosuspensions have been studied at relatively low frequencies of 105 Hz. The real and imaginary shear moduli of these samples were obtained on equipment using the acoustic resonance technique. It was shown that the shear modulus and viscosity decreases with increasing shear deformation. The behavior of viscoelastic fluids near surfaces is similar to that of colloidal and polymer suspensions, suggesting that the liquid component is determined by the mechanical response of suspensions.

Study Design:We collected experimental data concerning vertebrae sizes and performed an investigation of these data for different patient ages by methods of mathematical statistics.Purpose:The standard dimensions of vertebrae and intervertebral discs are of major importance for obtaining a comprehensive understanding of spine diseases and their successful treatment. The purpose is to study these sizes for children at the age of 9–14 years.Overview of Literature:Unfortunately, this issue is poorly presented in the corresponding literature. There are no systematic results. Only particular cases are presented.Materials and Methods:Experimental is based on the: results of X-ray investigations of children spines. Theoretical background is given by methods of mathematical statistics.Results:Systematic description of vertebrae sizes for children of age 9–14 is given. This specific age interval is the most common period of initiation of various pathological deformations of human spine.Conclusions:The acquired data both reflect the process of spine growth and can serve for building correct mathematical models of a healthful or diseased spine.