Study on the biparametrical transudations circuits with distributed parameters

This paper highlights the methods of resenting mode in the transudation with distributed parameters. The transient parameters of the power supply were analyzed. It was discovered that resonance is provided in a small range of movement of the moving component of the sensor in known turbofan engines, indicating that the known techniques of sustaining the resonance mode are flawed. Further study should focus on developing novel methods for preserving resonance mode over the entire range of change of the converted value, general principles of turbojet engine construction, and a complete examination of their resonant circuits, according to the findings.

Demonstration of toroidal metasurfaces through near-field coupling of bright mode resonators

Bright mode resonances are not well-acknowledged for inducing mode hybridizations. However, we demonstrate multiple bright resonators coupled through electromagnetic fields can induce resonance mode hybridizations. Although one of the hybridized modes shows parallel magnetic moments but the other mode demonstrates anti-parallel magnetic moments leading to magnetic toroidal resonances. Normally excitation of toroidal modes demands complex structures and/or bright-dark mode interactions. However, in this work, we employ solely bright resonators to excite toroidal modes. Unlike bright-dark mode coupling, exclusive bright mode resonance coupling enables larger free space energy merging into the metasystem leading to stronger energy confinement in the metasurface array.

Purely elastic instabilities in the airways and oral area

The present study considers a shear-thinning viscoelastic liquid layer sheared by the air and flowing past a deformable-solid layer in the presence of a surfactant at the air–liquid interface to model the airflow in the oral area and airways. The stability analysis reveals the existence of purely elastic and unconditionally unstable ‘liquid elastic’ and ‘solid elastic’ modes. The mechanism responsible for the destabilisation of the solid elastic mode is the shear stresses exerted by the air on the liquid and by the liquid on the deformable solid while for the liquid elastic mode, the mechanism is the first normal stress difference across the air–liquid interface. The liquid and solid elastic modes undergo resonance, resulting in the ‘resonance mode’ of instability. The resonance mode exhibits a much higher growth rate than the liquid and solid elastic modes. The shear-thinning characteristic of the liquid and presence of the surfactant leads to enhancement in the growth rate of the resonance mode. An estimate shows a good correlation between the exhaled fluid particle (i.e. droplets and aerosols) diameters and the wavelength of the perturbations with maximum growth rate. In essence, the present analysis predicts that the airflow in the airways and oral area could lead to an elastic instability arising due to the elastic nature of the saliva, mucus and underlying muscle layers.

Determiantion of energy characteristics of material destruction in the crushing chamber of the vibration crusher

The crushing equipment is characterized by a significant energy-consuming system during the crushing workflow. The current trend in the development of such processes puts forward requirements for the development of new or improvement of existing energy-saving equipment. The essence of the solution to the problem in this work is determined by using resonant modes, which are inherently the most effective. The practical implementation of the resonance mode has been achieved taking into account the conditions for the interaction of the resonant vibration crusher with the material at the stages of its destruction. The degree of the stress-strain state of the material is taken into account, which was a prerequisite for identifying the potential for the development of a vibration load. Composed equations of motion based on a substantiated discrete-continuous model of a vibration crusher and processing material. An approach is applied to determine the stepwise destruction of the material with the determination of the required degree of energy. This methodological approach made it possible to reveal the nature of the process of material destruction, where energy costs at the stages of crack formation, their development and final destruction are taken into account. It was revealed that the greatest energy consumption during the operation of crushers goes into the kinetic energy of the crushing plates and the potential energy of deformation of the springs. The proposed model is common for any design of a vibration machine and its operating modes. The stable resonance mode has made it possible to significantly reduce the energy consumption for the course of the technological process of material grinding. The results obtained are used to improve the calculation methods for vibratory jaw and cone crushers that implement the corresponding energy-saving stable zones of the working process.

An acoustic absorbing metamaterial with multi-Helmholtz resonators at low-frequency underwater

An ultra-thin waterborne acoustic metamaterial (AM), which is made of steel and composed of multi-Helmholtz resonators (MHRs), is proposed to achieve perfect sound absorption at low frequencies, which are generated around the resonance mode. The average surface acoustic impedance of the metamaterial is almost perfectly matched with water impedance under the action of resonance among the HRs, thus the perfect sound absorption is achieved. The case of two resonators is taken as an example to verify the design idea. By adjusting HRs’ sizes in simulation, the sound absorption coefficient reaches 99.6% at low frequency of 2740 Hz with ultra-thin thickness less than [Formula: see text]. The abnormal physical properties of AMs are often accompanied by abnormal effective material parameters, which turn to be negative near the perfect sound absorption through inversion calculation. The HRs proposed are simple to fabricate, mechanically stable, and convenient to couple with other resonators to achieve low-frequency broadband sound absorption.

Spectral Shaping with Integrated Self-Coupled Sagnac Loop Reflectors

We propose and theoretically investigate integrated photonic filters based on coupled Sagnac loop reflectors (SLRs) formed by a self-coupled wire waveguide. By tailoring coherent mode interference in the device, three different filter functions are achieved, including Fano-like resonances, wavelength interleaving, and varied resonance mode splitting. For each function, the impact of device structural parameters is analyzed to facilitate optimized performance. Our results theoretically verify the proposed device as a compact multi-functional integrated photonic filter for flexible spectral shaping.