Oblique explicit wave solutions of the fractional biological population (BP) and equal width (EW) models

This research uses the extended exp-$( -\varphi(\vartheta ) ) $ ( − φ ( ϑ ) ) -expansion and the Jacobi elliptical function methods to obtain a fashionable explicit format for solutions to the fragmented biological population and the same width models that depict popular logistics because of deaths or births. In mathematical terminology, the linear, hyperbolic, and trigonometric equation solutions that have been found describe several innovative aspects from the two models. Sketching these solutions in different types is used to give them more details. The accuracy and performance of the method adopted show their ability to be applied to various nonlinear developmental equations.

A strength criterion for frozen clay considering the influence of stress Lode angle

To investigate the influence of stress Lode angle on frozen soil, a series of directional shear tests was conducted on artificial frozen clay at three temperatures (–6, –10, and –15 °C) and five stress Lode angles (θσ = –30°, –16.1°, 0°, 16.1°, and 30°) using a hollow cylindrical apparatus. An elliptical function was proposed according to the strength envelope evaluation with the mean principal stress (p) in the p–q plane. In addition, generalized nonlinear strength theory (GNST) was introduced in the π plane to describe the evolution of the strength envelope with increasing mean principal stress. Then a strength criterion for frozen clay in three-dimensional principal stress space was proposed by combining strength functions in the p–q and π planes. The temperature effect was also introduced into the strength criterion. The proposed strength criterion can predict the multi-axial strength characteristics of frozen clay and reveal the influence of the stress Lode angle.

PROPOSAL OF PROCEDURE FOR IDENTIFICATION OF MENÉTREY–WILLAM (M-W-3) PLASTICITY SURFACE OF HOMOGENEOUS AND HOLLOW MASONRY UNITS

The article presents the author’s proposal to determine the parameters of the Mentérey–Willam (M-W-3) plasticity surface of the homogeneous masonry elements made of autoclaved aerated concrete (AAC) and vertically hollow calcium-silicate (Ca-Si) masonry units. The uniaxial and triaxial tests of AAC samples in a standard Hoek’s cell was performed while the hollow units made of silicate were tested on a custom-made test stand. By performing statistical analyses, the shape of the meridians of the surface was determined, and then the eccentricity e of the elliptical function was identified.

A New Contact Model of Rough Surface Based on Analytical Method

In this paper, an analytical contact model is proposed to study the contact behavior between two rough surfaces. Elliptical function is employed to describe contact stiffness of a single asperity, and the contact area is characterized by polynomial function in elastoplastic deformation regime. Results show that the proposed model ensures the continuity and smoothness of contact variables across different deformation regimes for a single asperity. The accuracy of the contact model has been demonstrated by the good agreement between the proposed model and the existing statistical model. Influences of material properties on normal contact force and interfacial stiffness have been further studied using the established model.

A COMPACT INTEGRATION OF HIGH-TEMPERATURE SUPERCONDUCTING BANDPASS AND BANDSTOP FILTERS

Integration of a high-temperature superconducting (HTS) narrowband bandpass filter and a HTS bandstop filter onto a single piece double-sided YBCO thin film with 0.5mm-thick LaAlO 3 substrate has been carried out. The 8-pole bandpass filter was designed with a fractional bandwidth about 0.8%. A pair of transmission zeros was implemented, showing typical quasi-elliptical function characteristics. The bandstop filter has a high stopband attenuation (~70 dB ) to fulfill the special requirement of potential application in communications. Integration of the two filters was successfully achieved.