The purpose of this work is to study features of deformation at the room temperature by the method of uniaxial compression of alumina toughened zirconia ceramics (stabilized with calcium oxide) with different content of the silicon dioxide (CaO-ATZ+SiO2). It was found that SiO2 addition to the CaO-ATZ-ceramic ensured manifestation of the signs of plasticity at the room temperature, i.e., yield stage in the loading diagrams. The most pronounced plasticization was manifested at the silicon dioxide content of 4 mol. %. In this case, plastic deformation (calculated as the difference between deformations corresponding to the tensile strength and conditional yield strength) reached the 0.79 % value. In addition, introduction of the SiO2 additive (2 mol. % concentration) caused an increase in the ultimate compressive strength to the value of 2.66 GPa and ultimate strain to the value of 1.79 %. It was shown that exceeding the threshold value of the SiO2 concentration (by more than 4.5 mol. %) caused a sharp embrittlement of the CaO-ATZ+SiO2-ceramics. Discovered ceramics plasticity at the room temperature is explained by an increase in the tetragonal phase transformability of zirconium dioxide, which enhances the role of the transformation toughening mechanism. Plasticity margin of the composite ceramics based on the zirconium dioxide was achieved at the room temperature and provides a prospect for expanding the area of its practical applications
The paper studies acoustic signals in two modes of merging with water in a freely falling water droplet by the matched optical and acoustic methods. Only the primary sound packet was observed in the intrusive mode at the low drop speed, when the cavity was formed with a delay in the colored wake of the inflowing liquid. Experiments demonstrated the drop speed influence on the primary signal parameters. At the high droplet speed, the cavity started to form from the moment of the initial contact. The flow pattern became more complicated, the droplet substance was distributed over the emerged cavity surface and the grown crown in the form of separate fibers forming the line and mesh structures. The falling section of the primary acoustic signal was formed by a group of pulses with the complex spectral composition. Further, one or more low-frequency sound packets were registered after the pause. Spectral portrait of the secondary packets was related to the shape of the detached gas cavity. Smooth axisymmetric cavity was radiating the monochromatic packet. The complex-shaped cavity was transforming into a gas bubble and emitting the multi-frequency signal. Duration and amplitude of the secondary sound signals were depending on the transformation rate of the separated gas cavity into a smooth spheroidal bubble. The acoustic signal parameters were changing nonmonotonically with increasing velocity of the merging drop
In this report, powder of barium titanate (BaTiO3) was fabricated using the sol-gel method followed by a sintering process at 900 °C. X-ray diffraction (XRD) was carried out to determine the phase and the crystal structure of the barium titanate. XRD patterns were then refined using the Rietveld analysis method on Fullproof software. The results show the barium titanate (BaTiO3) phase has a tetragonal perovskite structure. EDAX and scanning electron microscope (SEM) were examined to analyze the chemical composition and morphology of the material powder respectively. The results showed that the powder barium titanate (BaTiO3) contains Ba, Ti, and O atoms. The crystallite size is 3 μm and the morphology look homogeneous. The structure factor obtained from the experiment is used to calculate the polarization hysteresis using Polydomain and Landau --- Khalatnikov models. The results of modeling using the structure factor approach using Landau --- Khalatnikov modified model and the Polydomain modified model showed the R-factor (Rwp) is 8.7 and 11.3 %
In this report, powder of barium titanate (BaTiO3) was fabricated using the sol-gel method followed by a sintering process at 900 °C. X-ray diffraction (XRD) was carried out to determine the phase and the crystal structure of the barium titanate. XRD patterns were then refined using the Rietveld analysis method on Fullproof software. The results show the barium titanate (BaTiO3) phase has a tetragonal perovskite structure. EDAX and scanning electron microscope (SEM) were examined to analyze the chemical composition and morphology of the material powder respectively. The results showed that the powder barium titanate (BaTiO3) contains Ba, Ti, and O atoms. The crystallite size is 3 μm and the morphology look homogeneous. The structure factor obtained from the experiment is used to calculate the polarization hysteresis using Polydomain and Landau --- Khalatnikov models. The results of modeling using the structure factor approach using Landau --- Khalatnikov modified model and the Polydomain modified model showed the R-factor (Rwp) is 8.7 and 11.3 %
This paper proposes Maine Coon and Perognathinae based optimization (MPO) algorithm for solving the power loss lessening problem. Usual behaviour between Maine Coon and Perognathinae is imitated to formulate the MPO algorithm. In the proposed MPO, the crusade of Maine Coon towards Perognathinae as well as the spurt of Perognathinae in the direction of anchorages is replicated. Proposed MPO is population-based procedure which is premeditated by imitating the natural actions of a Maine Coon assaults on Perognathinae and absconding of Perognathinae to the anchorage. The exploration agents in the projected MPO algorithm are alienated into two clusters of Maine Coon’s and Perognathinae that examine the problem exploration space with arbitrary activities. The projected MPO algorithm apprises population associates in two segments. In the principal segment, the crusade of Maine Coon’s in the direction of Perognathinae is modelled, and in the subsequent segment, the absconding behaviour of Perognathinae to anchorages to protect its life is designed. From a scientific fact of opinion, every associate of the populace is a recommended solution to the problem. In detail, an associate of the population postulates standards for the problem parameters rendering to its location in the exploration space. Proposed MPO algorithm is appraised in IEEE 30 bus system and IEEE 14, 30, 57, 118, 300 bus test systems without considering the voltage constancy index. True power loss lessening, voltage divergence curtailing, and voltage constancy index augmentation has been attained
