As a result of anthropogenic activities, the environment is polluted by heavy metals. The most important task is to find methods to control their content in water. Track-etched membranes (TeMs) can be relatively easily modified by nanometer layers of functional materials with using the Langmuir‒Blodgett technique, which makes it possible to specifically change the structural, selective properties of the membrane surface and obtain new materials with desired properties. The aim of the work was to develop flexible sensors for the analysis of lead ions in water based on poly(ethylene terephthalate) (PET) TeMs with perfluorodecanoic acid (PFDA) nanolayers. Techniques for modifying TeMs based on PET with a monolayer coating based on PFDA by the Langmuir‒Blodgett method, and with two-layer coatings, formed by soaking PET TeMs/PFDA in xylenol orange solutions have been developed. The microstructure and local mechanical properties of the sensor surface were studied by atomic force microscopy, and the wettability and values of the specific surface energy of PET TeMs before and after modification were evaluated using the ''sessile'' drop method. Based on the measurement of  electrochemical  characteristics,  it  was  found  that PET TeMs/PFDA have a higher response of electrochemical characteristics compared to PET TeMs and PET TeMs/PFDA/XO. The limit of detection for lead ions in aqueous solutions at pH = 12 was of 0.652 µg/l within 5 measurements.

Strict requirements for determining of gases concentration in the working environment it is relevant to develop of semiconductor sensors which provide rapid response and safety of personnel in industrial and domestic premises. The aim of the work was to study gas-sensitive and dynamic characteristics of high-sensitive low-power sensors made on thin nanoporous substrates with gas-sensitive layers of semiconductor metal oxides. The low-power semiconductor gas sensor on the anodic alumina substrate has been developed. Sensors with gas-sensitive semiconductor metal oxide layers based on In₂O₃+Ga₂O₃, In₂O₃+SnO₂ and SnO₂+Pd deposited from aqueous solutions with subsequent firing on sensor information electrodes are manufactured. Studies of gas-sensitive characteristics have shown that sensors with SnO₂ films with the addition of Pd nanoparticles have maximum sensitivity of about 85 % and high response rate to 10 ppm H₂ at 410 °C. The maximum sensitivity of 250 % to 10 ppm CO at 220 °C was shown by films based on In₂O₃+SnO₂, the response time τ₉₀ was 5 s, while the sensitivity of In₂O₃+Ga₂O₃ and SnO₂+Pd was 30–50 % at 410–420 ºC. Semiconducting metal oxides In₂O₃+Ga₂O₃ (70 % at 420 °C) and In₂O₃+SnO₂ (30 % at 250 °C) showed lower sensitivity to hydrogen, with response time τ₉₀ = 20 s. The sensors power consumption in all measurements was 28–60 mW. Semiconductor gas sensors with low energy consumption can be used in the systems development that monitor the carbon monoxide concentration in the work area, as well as detect ignition's early stages.

Video camera, are installed on platforms of gyroscopic stabilization systems in order to improve the quality of visual information and provide the required orientation of the optical axis. The goal of the work was to develop a mathematical description that allows evaluating accuracy of gyroscopic stabilization systems for a video camera on a moving object, built on micromechanical sensors for primary information. A biaxial system for gyroscopic stabilization of a video camera on a moving object is considered. A mathematical description of the channel of the stabilization system with control over angle and angular velocity is given. Measuring the angle of deviation of the platform from the horizontal plane and its angular velocity is provided by micromechanical accelerometers and gyroscopes, respectively. Physical nature of the synchronous errors' occurrence in the stabilization system during angular vibrations of a moving object is explained. An assessment of the synchronous error of the stabilization system when the object oscillates with a frequency of 30 Hz is given. An analytical relationship is presented for estimating of the stabilization system errors is caused by random errors of gyroscopes and accelerometers. It is shown that if the platform is stabilized only by gyroscope signals containing random errors such as white noise in the measurements, this will lead to the platform drifting with a standard deviation proportional to the square root of time. In this case, the constant disturbing moment is not processed. A mathematical description of the “blurring” of the video camera image during platform vibrations caused by random errors in inertial sensors is given. Effect of image blur for various platform oscillation parameters is illustrated.

It is necessary to control temperature using thermoelectric sensors for steel products surface alloying in conditions of microarc heating. The using S-type thermocouples possibility has been substantiated, main factors affecting the measurement results have been established, and the the reproducibility index functional dependence on the measured temperature has been determined, as a result of previous studies. However, additional influencing factors that may affect to the heating process kinetics and the temperature measurements results were not taken into account. The purpose of the work was a steel temperature measurement results uncertainty generalized assessment during microarc heating, taking into account most complete influencing factors set. Influencing factors comprise: average coal powder particle size (X1), sample diameter (X2); chromium content in steel (X3 ). The measurement error was denoted Y. The dependence is obtained: Y = –4.032X1 – 0.095X2 + 0.0058X3 + 3.414. Thus, in the studied range of values, an increase in the powder particle and the samples diameter size leads to a decrease in the measurement error, and the chromium content increase leads to its increase. Therefore, the temperature measurement error during microarc heating can be reduced with decrease the sample heating rate, as well as with increase the heat transfer intensity from its surface to the material depth due to an increase the size, and, accordingly, the processed products mass. Next, the studied factors values distribution laws were evaluated. For X1 and X2, the normal distribution law is adopted, for X3 – uniform. Taking into account each factor's influence coefficients, and the total uncertainty estimate introduced assessment by them, a generalized uncertainty estimate was found: U = 1.1 °C. The microarc heating temperature measurement method quantitative assessment detailed of the accuracy makes it possible to take into account all significant influencing factors and their total measurement uncertainty contribution. The obtained temperature measurement's total uncertainty value from the three studied factors can be used as a priori information as a type B uncertainty during the microarc saturation process.

Optical glass ceramics based on oxyfluoride glasses activated by rare earth ions have attractive properties for development of lasers and near-infrared amplifiers, since they combine properties of fluoride crystals with low phonon frequencies and chemical and mechanical properties of oxide matrices. Spectroscopic properties of activator ions in crystalline and glass phases of glass-ceramics can differ significantly. Thus, it is possible to determine impurity ions’ distribution between these phases by means of absorption or luminescence spectra analysis. The main goal of this work was to develop a method for determining the concentration of Tm³⁺ and Ho³⁺ ions in the crystalline, PbF₂ and glassy phases of glass ceramics after secondary thermal treatment of thulium-doped and thulium-holmium co-doped oxyfluoride glasses. Spectroscopic characteristics of oxyfluoride glasses activated by Tm³⁺ ions and co-activated by Tm³⁺ and Ho³⁺ ions, as well as glass ceramics obtained from the original glasses as a result of secondary heat treatment were studied. It was established by X-ray phase analysis method that under certain heat treatment conditions crystalline β-PbF₂ phase is formed in those glasses. Absorption and luminescence spectra of Tm³⁺ and Ho³⁺ impurity ions in the original glass and in β-PbF₂ crystals were compared with their ones in glass ceramics. A method for determining the concentration of ions in the crystalline and glass phases of glass ceramics was proposed on the basis of this comparison. Dependence of Tm³⁺ and Ho³⁺ ions distribution between the glass and crystalline phases on different regime of glasses' secondary heat treatment was studied.

Crack resistance of two types of glass was studied – cover glass (0.17 mm thick) and slide glass (2 mm thick) using an improved technique through the use of the probe methods, which makes it possible to increase the accuracy of determining the crack resistance of glass. Colorless silicate glass was used. Crack resistance was determined by the Vickers pyramid indentation method. Microstructure of glasses surface and deformation region after indentation were studied using an atomic force microscope. Mechanical properties of glasses were determined by nanoindentation. Surface relief of a glass slide is rougher than that one of a cover glass. Roughness R_z for a cover glass is less than for a slide glass. Specific surface energy value of 0.26 N/m is higher for the slide glass compared to the coverslip. One elastic modulus value E of the cover glass is 48 GPa, and that one of the slide glass is 58 GPa. The microhardness value H is almost the same for by the glasses and amounts to 6.7 GPa for a slide glass and 6.4 GPa for a cover glass. Atomic force microscope images of deformation region after indentation with a Vickers pyramid show that the first cracks appear at a load of 1 N on the slide glass, and at 2 N on the cover glass. At a load of 3 N, the cover glass is destroyed. Based on the results of crack resistance calculations it was found that critical stress intensity coefficient K_IC values are 1.42 MPa∙m^1/2 for a glass slide, and 1.10 MPa∙m^1/2 for a cover glass.

Express determination of the elemental composition of steels and iron-based alloys is an urgent problem. Laser induced breakdown spectroscopy can be applied for its decision. The disadvantage of single- and multivariate modeling the elemental composition of steels is the semi-quantitative accuracy of the models. The aim of the study was developing quantitative multivariate calibrations of the concentrations of a set of chemical elements sufficient to identify low-alloy steels using low-resolution emission spectra. The multivariate partial least squares method was used to create the calibrations. Reducing the effect of redundancy of wideband emission spectra on the results of quantitative analysis was achieved by searching combination moving window containing one spectral variable more than the optimal number of latent variables for the wideband multivariate model. Further improvement of calibration accuracy was achieved by using the adaptive iteratively reweighted penalized least squares algorithm for spectrum baseline correction. Based on the laser emission spectra of 65 reference samples of low-alloy steels registered in the wavelength range 172–507 nm with a spectral resolution of 0.5 nm and a step of 0.1 nm, the following calibration models were developed: for carbon concentration with a root mean square error 0.059 % in the range ≤ 0.8 %, for manganese – 0.02 % and 2.0 %, respectively, chromium – 0.009 % and 1.0 %, silicon – 0.021 % and 1.2 %, nickel – 0.04 % and 0.8 %, copper – 0.019 % and 0.5 %, vanadium and titanium – 0.005 % without range limitation. The obtained multivariate models are quantitative for eight elements. These models give the possibility to identify the grade of low-alloy steels in an express manner at the stages of production or recycling.