The study of thermoelectric properties of crystalline semiconductors with structural defects is of practical interest in the development of radiation-resistant Peltier elements. In this case, the spectrum of energy levels of hydrogen-like impurities and intrinsic point defects in the band gap (energy gap) of crystal plays an important role. The purpose of this work is to analyze ...

Radionuclide 238U is one of the most important radioactive elements that must be controlled in nuclear power engineering, geological exploration, control of radioactive contamination of soils and raw materials used in construction. The most optimal way to control 238U is to use the 234mPa radionuclide, the activity of which, due to its short lifetime (≈ 1.2 min), is unambiguously ...

The nature of the molten electrode metal melting and transfer is the main process parameter of manual metal arc welding (MMA) with coated electrodes. It significantly affects the efficiency of the welding process. For this reason the relevant task is to identify the parameters of the transferred molten electrode metal drops and their further transfer into the weld pool with maximum ...

In this paper authors investigate laser beam shutting system of a new design. The scheme of the investigated laser beam shutter and working principle are explained. According the experi-mental research results of the developed laser beam shutting system was performed.

The work purpose is the development of BSUIM-1 and BSUIM-2 complexes for training specialists in the aerospace industry with the used engineering test beds and experimental facilities. Two sets of nanosatellite engineering models and ground stations had developed. They allow testing hardware and software of the onboard equipment and payload, simulating operation modes, and flight ...

The main characteristics of airborne micro/nanoparticles, their impact on human health and air quality standards are presented. International standards classify microparticles by size (PM10, PM2.5, PM1, UFP), establish maximum allowable concentrations and control methods. Particular attention is paid to carbonand virus-containing microparticles control. To monitor the air environment ...

The method of averaging modified periodograms is one of the main methods for estimating the power spectral density (PSD). The aim of this work was the development of mathematical and algorithmic support, which can increase the computational efficiency of signals digital spectral analysis by this method. The solution to this problem is based on the use of binary-sign stochastic ...

The aim of this work is to investigate the influence of vibrations on the material of the board. For that purpose a cascade of navigation devices boards was installed on the vibrational stand. Experiments were performed in the 0,5–10 Hz vibrational diapason range; 0–3 V voltage range; 0 – +45 °C allowed temperature range. Amplitude method was applied to determine the coordinates ...

Solving the problems of spectral processing of single and quasi-periodic signals in measurement and diagnostic systems is directly related to their isolation against the background of external interference or noise. The purpose of this work was to study single and quasi-periodic signals, i. e. signals limited in time, presented as separate components; development of a mathematical ...

The widespread use of polyolefin foams in strategically important industries is due to their high thermal, sound and vibration insulation properties. The aim of the work was to evaluate the non-uniformity of elastic properties over the area of sheets of polyolefin foams of various types using the acoustic non-contact shadow amplitude method of testing and confirmation by the ...