Search

Yttrium (Y3+) substituted Co-Zn spinel ferrite nanoparticles with compositional formula Co0.9Zn0.2YxFe1.9-xO4 (x = 0.0, 0.015, 0.030, 0.045, 0.06) were synthesized by using sol-gel auto-ignition route. The structural and mechanical properties of Co-Zn ferrites were tailored by the replacement of Fe3+ ions by Y3+ ions. Rietveld refined X-ray diffraction patterns of all the samples confirm the cubic spinel structure. Lattice parameter increases with the substitution of Y3+ ions which may be due to the difference in ionic radii. The crystallite size obtained from XRD analysis is found in the nanometer range of 16.8 – 24.7 nm. Distribution of cations over tetrahedral – A and octahedral – B sites have been studied by using X-ray diffraction data and it is found that Y3+ ions prefers the octahedral – B site. Infrared spectra of all the samples were recorded in the wave number range of 300 cm−1 to 800 cm−1 which shows splitting of the two fundamental absorption bands. Two absorption bands (ν1 and ν2) observed in the range 380 – 610 cm−1 are belongs to tetrahedral – A and octahedral – B interstitial sites. The force constants (KO and Kt) and corresponding elastic parameters were determined by using IR data. The stiffness constant (C11), Young’s modulus (E), rigidity modulus (G), bulk modulus (B) and Debye temperature (θD) were found increases with the addition of Y3+ ions.

This paper presents a method for calculating the sensibility and inertia of net radiometer. The concept of lag coefficient of net radiometer is introduced. The effect of wind speed on the time course of the temperature difference between the plates of the net radiometer was investigated. It is presented that with the development of wind speed and sensibility, the lag coefficient of net radiometer decreases. The recommendations on the practical application of methods for automatically taking into account the inertia error of devices in production measurements are given.

The article presents physical modeling data for the passive method of induced polarization for the possibility of estimating the depth of immersion of the ore body simulator. Experimental observations were carried out on a laboratory tank filled with sand, the observation time for each measurement point was 180 s, the sampling frequency was 1 kHz. In the course of physical modeling, measurements of the induced polarization parameter were carried out in the absence of an ore body simulator, with its immersion by 10 cm and 20 cm, as well as with full immersion and immersion to a depth of 30 cm. As a result of physical modeling with an ore body simulator, the following results: the dependence of the induced polarization parameter was obtained with increasing depth; with increasing depth, the change in the induced polarization parameter decreases; the background value of the induced polarization parameter in the absence of an ore body simulator leads to a decrease in the sensitivity of the measurement equipment.

This paper is focused on the field of quantum computing which is an important area of research these days. The paper gives a brief history of this phenomenon and discusses how it has been developing since its conception. Furthermore, the paper describes the principles on which the quantity computer is built, such as qubits, entanglement, and superposition. It also discusses the necessity to build a quantum computer and how it could an improvement upon the existing computers. In addition, the paper covers some of the fields in which quantum computing could be particularly beneficial. Finally, some of the problems and challenges associated with the development of quantum computing are addressed.

The article presents data from field experimental observations using the passive method of induced polarization, at the Zhomart mine (Zhaman-Aibat deposit, Republic of Kazakhstan) on September 7-8, 2021. Profiling was carried out with a step of 50 meters, non-polarizing electrodes of the “VITR” brand were used as electrodes. The signals were recorded using a specialized precision 24-bit analog-to-digital converter. In the course of field observations, a profile characteristic was obtained in terms of the induced polarization parameter. An analysis of the profiling graph shows that the obtained profile characteristic marks the presence of an ore body with two peaks with values of 0.35 and 0.32, which, when using a three-electrode differential setup, indicates the presence of polarization anomaly boundaries. Thus, the passive method of induced polarization makes it possible to register ore anomalies down to a depth of 600 m and makes it possible to detect copper-bearing ores.

The article deals with the problem of metrological support of innovative technologies, in particular, related to the production of promising renewable energy sources such as biofuels. In the process of biofuel separation, it is very important to monitor various technological parameters: pressure, flow, liquid level, temperature, etc. For this purpose, measuring devices are used as part of the automation of technological processes. At the same time, flow turbulence can have a significant impact on the accuracy of the readings of these devices. Often, the transition from laminar to turbulent flow is associated with the formation of a vortex when overcoming the flow of various constrictions at the outlet of the installations. The paper considers a method for preventing the formation of vortices through the use of a anti-vortex device (AVD). Computer modeling of the fluid flow in the SolidWorks software package was carried out in order to determine the optimal geometric characteristics of the AVD. In particular, the influence of the gap in the AVD and its plate diameter was studied.

The degree of corrosion damage by microorganisms to the concrete wall of the basement is investigated. The biofilm on the surface of the concrete wall under study is formed by micromycetes Aspergillus niger, bacteria Bacillus subtilis, Actinomycetes, nitrifying bacteria Nitrosomonas, lactic acid bacteria Lactobacillus and sulfate-reducing bacteria Desulfovibrio. The waste products of microorganisms consist of organic acids secreted by micromycetes of Aspergillus niger, ammonium ions, carbonate-, nitrate-, sulfide-ions secreted by bacteria. To establish the corrosion state of steel reinforcement in biodegradable concrete, the electrode potential was measured. The established values of the surface potential of steel reinforcement are in the range -351 ÷ -376 mV. This suggests that the probability of local corrosion of steel reinforcement in a biodegradable concrete wall is strong. It will take about 20 years to achieve an aggressive concentration of organic acids at the surface of steel reinforcement in biodegradable concrete with a layer thickness of 5 cm. However, in conditions of constant moistening of the concrete surface, this period is reduced to 10-11 years. The predicted rate of local corrosion of steel reinforcement in concrete exposed to microorganisms is at least 0.2 mm/year. It was found that the depth of concrete destruction under the influence of microorganisms, mainly micromycetes Aspergillus niger, for 20 years is 1.3 cm; for 50 years is 2.1 cm.

A new approach for modeling steady state inductively coupled radio frequency discharges at low pressure is described. A simple one-dimensional model is considered, which includes Maxwell’s equations and the electron balance equation with boundary conditions of the third kind. It is shown that the system of boundary value problems is a two-parameter partial eigenvalue problem. The smallest eigenvalue of the problem is the boundary value of the magnetic field strength. The second parameter of the problem is the concentration of electrons at the center of the plasma bunch. The developed approach makes it possible to calculate the inductor current required to maintain a steady state of the discharge. The results of calculations of the dependence of the inductor current, electron density, electric and magnetic fields on pressure are presented.