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The work deals with the study of secondary-phase precipitation in binary and ternary zirconium-based alloys with extra-small content of doping within the framework of the phase-field approach. Developed phase-field model is applied to study β-phase precipitation in the model system of commercial Zr–Nb–Sn and Zr–Nb alloys at thermal treatment. An analysis of local rearrangement of doping and equilibrium vacancies during precipitation is provided. Kinetics of precipitation, size and distribution of the precipitates, concentration of the species in precipitates and matrix are studied. Mechanical response including the plastic deformations in precipitated solid is discussed. As shown, the yield-strength change increases during precipitation. Yield and ultimate strength are studied at different shear rates for the annealed alloy. Formation and growth of slip planes and dislocation loop–precipitate interaction governed by elastic-moduli difference is analysed. As shown, the emergence of dislocation loops around precipitates follows the Orowan’s mechanism. Modelling the radiation-induced precipitation during neutron irradiation of zirconium alloys with low content of doping is performed within the framework of the developed phase-field model by taking into account ballistic mixing and the dynamics of point defects with their sinks. As shown, in a sample initially containing precipitates of the secondary phase, irradiation results in the dissolution of precipitates at small doses and reprecipitation with dose accumulation. Analysis of precipitation dynamics and statistical distributions of precipitates with local rearrangement of non-equilibrium vacancies around precipitates at neutron irradiation is provided. As shown, the competition between the ballistic mixing and the thermodynamic force plays a major role in kinetics of radiation-induced precipitation and precipitates’ dissolution. The estimation of mechanical properties of Zr–Nb alloy during irradiation under reactor conditions is provided.

Underground pipelines during operation are affected by mechanical and corrosive factors. The susceptibility of cathodically protected pipe to hydrogen degradation increases, which contributes to stress-corrosion cracking. It is believed that the main factor in pipeline steels degradation is deformation aging, which increases strength and reduces plasticity. Volume microdamages also develop in long-time exploited steels. But in many cases, the base metal and welded joints of long-term operated pipelines retain satisfactory performance. Due to the high value of viscosity and plasticity of the metal in an as-received state, the metal state of long-term operated gas pipelines can be considered satisfactory.

Assessing the effects that nonstationary dynamic processes have on the durability of structural elements belongs to an important trend in modern dynamics and technical diagnostics of machines. Normally, fatigue strength calculations are performed taking into account only periodically variable stresses, as steady operating modes of machines are much longer in comparison with transient modes. However, a significant role in fatigue failure in machines and engineering structures is also played by nonstationary loads. This is explained by emerging intensive oscillations in the mechanical system during accelerating, braking, or changing the operation mode of a machine unit, which often lead to the accumulation of fatigue damages in the materials of parts in heavy loaded assemblies. The combination of stationary and nonstationary dynamic loads manifests itself, particularly in drilling rigs, where technological cycles include steady motion modes, starts, and stops. This paper represents a generalized mathematical model describing nonstationary processes in the lift system of a drill rig, which considers the relationship between electromagnetic processes in asynchronous motors and mechanical oscillatory phenomena, with the purpose of determining dynamic loads and stresses in structural elements of the rigs. Nonlinear physical systems include mechanical members with both concentrated and clearly expressed distributed parameters. The durability of structural elements is evaluated by means of a computer algorithm for analysis of crack growth rates using the NASGRO equation obtained with the presence of plastic deformation zones. An example of the crown block axis illustrates the influence of nonstationary dynamic processes in drill rigs on the durability of structural elements.

Ensuring noise immunity is one of the main tasks of radio engineering and telecommunication. The main task of signal receiving comes down to the best recovery of useful information from a signal that is destructed during propagation and received together with interference. Currently, the interference and noise control comes to the fore. Modern elements and methods of processing, related to intelligent systems, strengthen the role of the verification and recognition of targets. This makes noise control particularly relevant. The most-important quantitative indicator that characterizes the quality of the useful signal is the signal-to-noise ratio. Therefore, determining the noise parameters is very important. In the present paper, a signal model is used in the form of an additive mixture of useful signals and Gaussian noise. It is an ordinary model of a received signal in radio engineering and communications. It is shown that the phase portrait of this signal has the shape of an ellipse at the low noise level. For the first time, an expression of the width of the ellipse line is obtained, which is determined by the noise dispersion. Currently, in electroencephalography, diagnosis is based on the Fourier transform. But, many brain diseases are not detected by this method. Therefore, the search and use of other methods of signal processing is relevant.

We provide a computational study of a change in the morphology of a growing thin film during condensation caused by electromigration effects. It will be shown, that separated circular adsorbate islands, realized in an isotropic system, become elongated in the direction of the applied electrical field. We discuss the dependence of the critical value of the strength of the applied electrical field, responsible for the formation of percolating adsorbate islands, on main control parameters. This study provides insight into details of electromigration effects during the self-organization of adatoms into percolating adsorbate islands during condensation from the gaseous phase. We will show that the elongated morphology of adsorbate islands remains stable if the electric field is turned off.

Plasma electrolytic oxidation has been used to create a sublayer on aluminum alloy to form a composite coating to improve the corrosion properties of the processed material. The evolution of protective characteristics of the resulting coatings were examined by potentiodynamic polarization during the exposure in a salt spray chamber. The absence of pittings after a 10-day test for the entire series of composite coatings on aluminum alloy confirms the high level of barrier properties of the coated samples.

The paper reveals the changes in corrosion properties of the samples with composite coating subjected to atmospheric corrosion test for 6 months. Composite coating (CC) was formed by treatment of oxide layer obtained by plasma electrolytic oxidation (PEO) with suspension of superdispersed polytetrafluoroethylene microparticles (SPTFE) in polyvinylidenefluoride (PVDF). The corrosion current density was compared for the composite coatings, PEO-coated and untreated samples. It is shown that corrosion current density for the sample with СC tested for 6 months (2.9·10–11 A·cm–2) is more than 3 orders of magnitude lower in comparison with the sample with PEO-layer (3.5·10–8 A·cm–2) and almost 6 orders of magnitude less than for uncoated aluminium alloy (1.7·10–5 A·cm–2).

The paper presents the results of an evaluation of the tribological characteristics of samples with composite coatings during 12 months of atmospheric corrosion. Composite coatings were obtained by treating oxide layer formed by plasma electrolytic oxidation (PEO) with fluoropolymers: superdispersed polytetrafluoroethylene (SPTFE) or polyvinylidene fluoride (PVDF), as well as a suspension of SPTFE in PVDF. It was found that the composite coatings formed in suspension with a ratio of PVDF to SPTFE 1:5 demonstrate the best tribological performance among the studied samples and characterizes by initial coefficient of friction 0.006–0.010. It is shown that samples with composite coatings have 1–1.5 orders of magnitude lower wear rate (9.7∙10⁻5–4.4∙10⁻4 mm3/(N·m)), in comparison with the PEO-treated sample (3.9·10⁻3 mm3/(N·m)).

The entropy-oriented approach called security- or cybersecurity-informed safety (SIS or CSIS, respectively) is discussed and developed in order to analyse and evaluate the safety and dependability of autonomous transport systems (ATSs) such as unmanned aerial vehicles (UAVs), unmanned maritime vehicles (UMVs), and satellites. This approach allows for extending and integrating the known techniques FMECA (Failure Modes, Effects, and Criticality Analysis) and IMECA (Intrusion MECA), as well as developing the new SISMECA (SIS-based Intrusion Modes, Effects, and Criticality Analysis) technique. The ontology model and templates for SISMECA implementation are suggested. The methodology of safety assessment is based on (i) the application and enhancement of SISMECA considering the particularities of various ATSs and roles of actors (regulators, developers, operators, customers); (ii) the development of a set of scenarios describing the operation of ATS in conditions of cyberattacks and physical influences; (iii) AI contribution to system protection for the analysed domains; (iv) scenario-based development and analysis of user stories related to different cyber-attacks, as well as ways to protect ATSs from them via AI means/platforms; (v) profiling of AI platform requirements by use of characteristics based on AI quality model, risk-based assessment of cyberattack criticality, and efficiency of countermeasures which actors can implement. Examples of the application of SISMECA assessment are presented and discussed.

The use of energy (and renewable energy, in particular) plays an important role in agriculture, where technologies are also being improved from year to year—agricultural production is growing, and machinery and systems are becoming more autonomous and robotic, where it is no longer possible to do without complex computing, optimization, planning, and working with large amounts of data [...]

This work reports on the investigation of sensory properties of thiacalix[4]arene molecules towards volatile halogen-aromatic compounds. Experiments were carried out using the 8-channel sensory system based on Quartz Crystal Microbalance (QCM) technique. Kinetic responses, concentration dependences and detection limit have been obtained. It has been shown that interaction of the sensitive layer with the analyte molecules is substantially defined by the chemical structure of thiacalix[4]arene. Thus, thiacalix[4]arene materials considered in this paper are of great interest for application in the sensory systems of “Electronic Nose” type.

The article analytically summarizes the idea of applying Shannon’s principle of entropy maximization to sets that represent the results of observations of the “input” and “output” entities of the stochastic model for evaluating variable small data. To formalize this idea, a sequential transition from the likelihood function to the likelihood functional and the Shannon entropy functional is analytically described. Shannon’s entropy characterizes the uncertainty caused not only by the probabilistic nature of the parameters of the stochastic data evaluation model but also by interferences that distort the results of the measurements of the values of these parameters. Accordingly, based on the Shannon entropy, it is possible to determine the best estimates of the values of these parameters for maximally uncertain (per entropy unit) distortions that cause measurement variability. This postulate is organically transferred to the statement that the estimates of the density of the probability distribution of the parameters of the stochastic model of small data obtained as a result of Shannon entropy maximization will also take into account the fact of the variability of the process of their measurements. In the article, this principle is developed into the information technology of the parametric and non-parametric evaluation on the basis of Shannon entropy of small data measured under the influence of interferences. The article analytically formalizes three key elements: -instances of the class of parameterized stochastic models for evaluating variable small data; -methods of estimating the probability density function of their parameters, represented by normalized or interval probabilities; -approaches to generating an ensemble of random vectors of initial parameters.

This work is devoted to a comprehensive detailed study of a pure zirconium with non-equilibrium point defects induced by irradiation within the framework of the multiscale modelling scheme by using quantum-mechanics methods, molecular dynamics, and the Monte-Carlo methods based on the Langevin dynamics. By using ab-initio calculations, the structural, electronic, and energy properties of a pure zirconium with isolated vacancies and their clusters are studied. The lattice-parameter change in pure zirconium with different concentrations of isolated vacancy and different configurations of di- and trivacancies is discussed. The vacancy-formation energy in a pure zirconium is obtained. Stability of small vacancy clusters containing divacancy characterized by different distances between two vacancies as well as trivacancies of different configuration is analysed. Distributions of electron density, band structure, and Fermi surface for pure zirconium with isolated vacancy are studied in detail. We calculate the dependence of the Fermi energy of a zirconium crystal, whose unit cell contains a vacancy cluster, on the number of vacancies in the cluster. Cascade formation, development, and annealing in pure zirconium crystals irradiated in different irradiation conditions are studied within the framework of the molecular-dynamics simulations. Statistical and geometric properties of cascades are examined in detail by varying sample temperature, energy of primary knocked atom, and direction of its motion. A possibility of channelling at cascades’ development resulting in formation of crowdions is shown. A change in statistical properties of the crystal during cascade development and relaxation time of cascades is calculated. Dependence of formation energy of point defects and vacancy clusters on temperature is discussed. Spatial self-organization of an ensemble of point defects in α-zirconium irradiated by fast neutrons by using reaction rate theory is studied. In our consideration, we take into account elastic properties of the medium due to defects’ presence and sink density dynamics. We consider dynamics of the system with uniform distribution of point defects and spatially extended system at different irradiation regimes (by varying irradiation temperature and dose rate). As found, the point defects’ patterning is accompanied by a formation of vacancy clusters. The distribution of elastic fields with the self-organization of a vacancy ensemble in a pure zirconium subjected to shear and cyclic deformation and the impact of irradiation on the mode of deformation of zirconium are studied.

Green synthesis of nanoparticles is a widely researched and popular direction in the development of nanotechnology. It is a simple, cheap and effective method for obtaining nanoparticles with interesting biological properties. In light of the development of antibiotic resistance to important clinical strains of bacteria, this method was used in the present study to obtain silver nanoparticles with antibacterial activity. The aim of this study was to synthesise silver nanoparticles with antibacterial action by yeast in a process known as “green synthesis”. We are also considering the prospect of using silver nanoparticles as an antibacterial substance for drug development. The production of nanoparticles was confirmed by UV spectroscopy. Staphylococcus aureus ATCC 25923 and Escherichia coli ATCC 25922 test strains and Staphylococcus aureus 1536 and Klebsiella pneumoniae 520 clinical isolates were used to study the antibacterial effect. The effect of synthesised nanoparticles on the metabolic activity of bacterial cells and their ability to adhere, as well as the minimum inhibitory concentrations (MICs) of synthesised nanoparticles for each of the strains, were determined. Following UV spectroscopy, the nanoparticles obtained were found to have a pronounced peak in optical absorption at 400 nm, corresponding to the plasmon resonance of silver nanoparticles, and demonstrated a high antibacterial effect against all the strains studied.

We perform a comprehensive study of noise-induced effects in a stochastic model of reaction-diffusion type, describing nano-structured thin films growth at condensation. We introduce an external flux of adsorbate between neighbour monoatomic layers caused by the electrical field presence near substrate in plasma-condensate devices. We take into account that the strength of the electric field fluctuates around its mean value. We discuss a competing influence of the regular and stochastic parts of the external flux onto the dynamics of adsorptive system. It will be shown that the introduced fluctuations induce first-order phase transition in a homogeneous system, govern the pattern formation in a spatially extended system; these parts of the flux control the dynamics of the patterning, spatial order, morphology of the surface, growth law of the mean size of adsorbate islands, type and linear size of surface structures. The influence of the intensity of fluctuations onto scaling and statistical properties of the nano-structured surface is analysed in detail. This study provides an insight into the details of noise induced effects at pattern formation processes in anisotropic adsorptive systems.

A generalized model to study dislocation loops growth in irradiated binary Zr-based alloys is presented. It takes into account temperature effects, efficiencies of loops to absorb point defects dependent on the loop size, an influence of locality of grain boundary sink strength, and concentration of the alloying element. This model is used to describe the dynamics of loop radii growth in zirconium-niobium alloys under neutron irradiation at reactor conditions. A growth of both loop radii and strains is studied at different grain sizes, location from grain boundaries, and concentration of niobium. It is shown that locality of grain boundary sinks results in a non-uniform deformation of the crystal inside the grains. Additionally, an introduction of niobium as an alloying element decreases the loop radii but promotes the growth of local strains inside the grains.

The productivity of most grain cleaning machines seems to be directly related to the efficiency of vertical pneumatic separation ducts. Nevertheless, improvement is accompanied by an increase in the load of the vertical duct, the design of which is limited by the width of the grain cleaning machines. This requires an increase in the thickness of the layer of grain mixture that enters the working area of the duct, which significantly worsens the conditions of separation of its components under the action of airflow. Particles of light impurities are unable to separate due to their retention by the grain medium. This reduces the quality of cleaning and requires appropriate scientific and technical solutions. The application of preliminary stratification of the granular mixture while increasing the concentration of light impurities in the top layer of the mixture seems to be a prospective method. The positive effect of the previous stratification on the intensity of redistribution of light impurity particles in the working zone has been theoretically considered and experimentally confirmed. Mathematical models were obtained to determine the trajectory of discussed particles, taking into account the previous stratification of mixtures, and the corresponding dependences were established. The influence of the initial coordination of the introduction of the particles of lightweight impurities, their sizes and densities, and technological and structural parameters of operation of the pneumatic separation duct were taken into account in the studies. The intensification of the process of cleaning grain from lightweight impurities in the working zones of pneumatic separation ducts of grain cleaning machines is theoretically substantiated.

Formalism is developed for description of microstructure transformations and phase separation in systems under irradiation. Investigation is made within the scope of the crystal phase-field method. This approach allows one to simulate materials on the molecular-dynamics spatial scales but on the diffusive-dynamics temporal scales. Considering a model for a periodic one-component system driven by both competing stochastic fluxes–thermally-stimulated and external ballistic mixing flues of atoms, conditions of microstructure-transformations’ appearance are determined. Analysis of the system on a mesoscopic level for a binary equiatomic system is performed. Reentrant character of phase-separation process is revealed. For systems with transient dynamics, for instance, with incommensurable time scales of propagation of disturbances, which are characterized by the memory effects, at presence of fluctuations of lengths of jumps of the atoms knocked-on by high-energy particles, occurrence of pattern-selection processes is revealed.

In this article we study transitions from low-density states towards high-density states in bistable plasma-condensate systems. We take into account an anisotropy in transference of adatoms between neighbour layers induced by the electric field near substrate. We derive the generalized one-layer model by assuming that the strength of the electric field is subjected to both periodic oscillations and multiplicative fluctuations. By studying the homogeneous system we discuss the corresponding mean passage time. In the limit of weak fluctuations, we show the optimization of the mean passage time with variation in the frequency of periodic driving in the non-adiabatic limit. Noise induced effects corresponding to asynchronization and acceleration in the transition dynamics are studied in detail.

We present a comprehensive study of voids formation, nucleation and growth in a prototype model of binary alloys subjected to irradiation by using a combined approach based on phase field and rate theories. It is shown that voids formation is caused by interaction of irradiation-produced vacancies through elastic deformation of a lattice and vacancy coupling with composition field of the alloy. Phase diagrams illustrating the formation of states related to solid solution, phase decomposition, and patterning are obtained. Formation of voids from supersaturated ensemble of vacancies is accompanied by composition rearrangement of alloy components. It was found that elastic inhomogeneity leading to the formation of anisotropic precipitates in an initially prepared binary alloy results in the formation of a void super-lattice under irradiation. It was shown that voids nucleate and grow with dose according to diffusion controlled precipitation processes, where universal dynamics of voids growth is revealed. Estimations of main quantitative and statistical characteristics of voids by using material parameters relevant to most of alloys and steels give good agreement with experimental observations.

In a given review, the description of the energy spectrum of electrons and the frequency spectrum of atomic vibrations of the crystal lattice are considered. The basic methods for investigation of influence of the anharmonicity effects on the physical properties of materials and a frequency spectrum of vibrations of the crystal lattice are reviewed. The self-consistent harmonic approximation, which is based on the method of double-time Green’s functions, are described. Within the scope of this approximation, the equation of motion for the ‘displacements–displacements’ Green’s functions, which is similar to the equation of motion in the harmonic approximation, is derived, but the force constants are renormalized and are determined by the thermodynamical averaging of second derivatives of potential rather than their equilibrium values. Appearances of the anharmonicity effects in the vibrational spectrum of the Ti0.93Al0.07 hexagonal close-packed crystal lattice as well as the electron-subsystem effects are investigated.

The main aim of the research is to develop the technique for laser remote ozone sensing in the upper troposphere – lower stratosphere by differential absorption method for temperature and aerosol correction and analysis of measurement results. The authors have determined wavelengths, promising to measure ozone profiles in the upper troposphere – lower stratosphere. We present the results of DIAL measurements of the vertical ozone distribution at the Siberian lidar station in Tomsk. The recovered ozone profiles were compared with IASI satellite data and Kruger model.

The applicability of a KTA crystal-based laser system with optical parametric oscillators (OPO) generation to lidar sounding of the atmosphere in the spectral range 3–4 μm is studied in this work. A technique developed for lidar sounding of trace atmospheric gases (TAG) is based on differential absorption lidar (DIAL) method and differential optical absorption spectroscopy (DOAS). The DIAL-DOAS technique is tested to estimate its efficiency for lidar sounding of atmospheric trace gases. The numerical simulation performed shows that a KTA-based OPO laser is a promising source of radiation for remote DIAL-DOAS sounding of the TAGs under study along surface tropospheric paths. A possibility of using a PD38-03-PR photodiode for the DIAL gas analysis of the atmosphere is shown.

The Siberian Lidar Station created at V.E. Zuev Institute of Atmospheric Optics and operating in Tomsk (56.5° N, 85.0° E) is a unique atmospheric observatory. It combines up-to-date instruments for remote laser and passive sounding for the study of aerosol and cloud fields, air temperature and humidity, and ozone and gaseous components of the ozone cycles. In addition to controlling a wide range of atmospheric parameters, the observatory allows simultaneous monitoring of the atmosphere throughout the valuable altitude range 0–75 km. In this paper, the instruments and results received at the Station are described.

A model for diffusion and phase separation, which takes into account hyperbolic relaxation of the solute diffusion flux, is developed. Such a ‘hyperbolic model’ provides analysis of ‘hyperbolic evolution’ of patterns in spinodal decomposition in systems supercooled below critical temperature. Analytical results for the hyperbolic model of spinodal decomposition are summarized in comparison with outcomes of classic Cahn−Hilliard theory. Numeric modelling shows that the hyperbolic evolution leads to sharper boundary between two structures of a decomposed system in comparison with prediction of parabolic equation given by the theory of Cahn and Hilliard. Considering phase separation processes in stochastic systems with a field-dependent mobility and an internal multiplicative noise, we study dynamics of spinodal decomposition for parabolic and hyperbolic models separately. It is that the domain growth law is generalized when internal fluctuations are introduced into the model. A mean field approach is carried out in order to obtain the stationary probability, bifurcation and phase diagrams displaying re-entrant phase transitions. We relate our approach to entropy-driven phase-transitions theory.

A synergetic conception of plastic deformation is presented allowing for the defects’ interplay resulting in a phase transition. A qualitative-reconstruction pattern of imperfect condensed-matter structure in the presence of fluctuations in both 0-dimensional and distributed (extended) systems is considered. As shown, the system undergoes the reversible phase transitions under the increasing intensity of fluctuations, diffusion constituent and deformation-type external parameters. Within the framework of the synergetic approach based on the Lorenz system, a pattern of explosive crystallization is shown to be scripting the same way as the avalanches formation. The relationships are set between the exponent of a size distribution of avalanches, the fractal dimension of a phase space, characteristics of noise, the number of governing equations, the dynamical exponent, and the non-additivity parameter. As shown, the regime of self-organized criticality is associated with an anomalous diffusion processes.

Analytical approaches describing non-Fickian diffusion in complex systems are presented. The corresponding methods are applied to the study of statistical properties of pyramidal islands formation with interacting adsorbate at epitaxial growth. Using the generalized kinetic approach we consider universality, scaling dynamics and fractal properties of pyramidal islands growth. In the framework of generalized kinetics, we propose a theoretical model to examine the numerically obtained data for averaged islands size, the number of islands and the corresponding universal distribution over the island size.

The paper presents the results of laboratory experiments on measurement of absorption and extinction of radiation of the overtone СО laser at wavelengths used for sensing of methane and N2O in the mid-IR spectral range with the differential absorption (DIAL) method, as well as the concentrations of the studied gases reconstructed from the analysis of experimentally obtained absorption coefficients.