It is shown that when machining products from materials with heterogeneous structure, possibilities of management of a condition of a blanket are significantly limited. As an example of management, cutting processing of products from materials with heterogeneous structure – turning of high-strength flame evaporated coverings is considered.
Because for an amorphous component of heterogeneous coverings the lack of deformation hardening is peculiar considerable deformation of the cut-off material is observed at their processing and characteristic shaving is formed. Highintensity thermobaric impact on the processed heterogeneous material leads to partial crystallization in a thin blanket with the high content of an amorphous phase.
As a result of researches the criterion which quantitatively estimates the statistics, which complexly characterize uniformity of structure of materials and dispersion of their properties, is offered. The criterion allows defining ability of materials to be exposed to cutting without carrying out long experiments.

The paper is devoted to the problem of producing hard, wear-resistant materials by SHS-casting using centrifugal forces. We have developed a device for centrifugal SHS casting and initial compositions of the reactive iron-base charge.
A technology for producing coatings, materials and final products with a non-uniform distribution of strengthening particles over the specimen volume has been developed and tested in industrial conditions.
The microstructure and phase composition of the synthesized material with a non-uniform distribution of reinforcing particles is studied. The synthesized material implements the Charpy principle: dispersed hard carbide particles are distributed in a relatively soft matrix, which ensures high wear resistance.
By means of SHS casting, billets were obtained for producing a measurement instrument, namely a plug-type gauge, which successfully passed industrial tests at OJSC “VIZAS”. The tests shown that the hardness of all synthesized samples was in the range from 63 to 68 HRC and the number of measurements per 1 micron of wear on a diameter of15 mm was 2500 to 2700. Hence, the developed method made it possible to significantly increase the service life of the measuring tool: by a factor of 1.5 to 2.

The effect of electroerosive treatment of the surface of carbide plates from superhard nitride ceramics on their phase composition and vacuum soldering of cutting elements is studied. Studies of the surface quality and elemental composition have been carried out. The surface of the plates for soldering is processed by the method of electroerosive cutting with brass wire in water, as well as by the method of electroerosive direct burn-through using copper and graphite electrodes in kerosene. The microstructure and elemental composition of the surfaces of hard-alloy plates were investigated by scanning electron microscopy and energy-dispersive X-ray spectroscopy before and after their processing. The analysis of the obtained data indicates that the best results at electro-erosion treatment of the hard-alloyed plate and the strongest bonding of brazed materials are achieved using a copper electrode and brass wire, since this ensures maximum wetting of the plate surface with solder based on Cu–Ti–Sn and the absence of pores. The hard-alloy cutter plate and ceramic cutting element were joined by high-temperature brazing in vacuum. Tests of hard-alloy plates with brazed cutting elements showed that the roughness of the machined surface of workpieces made of ХВГ steel with hardness of HRC 47–62 and ШХ15 steel with hardness of HRC 57–58 corresponded to 6–8 purity class at cutting speed of 155–170 m/min. The wear of the cutter along the trailing edge of 0.4 mm served as a criterion for evaluation of the cutting properties of superhard materials according to the results of durability tests.

In the manufacture of implants that are subject to increased cyclic loads, cobalt-chromium alloys with high hardness- and wear resistance have recently been widely used. Roughness of working surfaces is one of the most important characteristics of such products. The traditional processes of finishing the surface of cobalt-chromium alloy implants are based on mechanical and electrochemical methods. The disadvantages of mechanical methods are low productivity, susceptibility to the introduction of foreign particles, difficulties in processing of complex geometric shapes. For electrochemical technologies the treated materials are considered intractable, harmful electrolytes, consisting of solutions of acids, are used in the process of polishing. As an alternative to existing methods, it was proposed to use an environmentally safe method of electrolytic-plasma polishing, the main advantage of which is the use of aqueous solutions of salts with a concentration of 3–5 % as electrolytes. According to the results of the technological process, it has been established that at most electrolyte-plasma polishing modes of cobalt-chromium alloys for medical purposes, a relief in the form of a grid of protrusions occurs on the surface, the origin of which can be explained by the heterogeneity of the material structure that occurs at the stage of casting. Moreover, the height of the formed relief protrusions has a direct impact on the amount of surface roughness. As a result of studies, electrolyte-plasma polishing process modes were established, ensuring the formation of a smooth surface without the presence of embossed protrusions, smoothing the microrelief with the removal of scratches resulting from pre-grinding, achieving a low roughness value (Ra 0.057 micron) and a high reflection coefficient (0.7), which fully meets the requirements for the surface of the implants.

Autonomous power supply system of modern mobile special-purpose equipment requires the development of electromechanical energy converters with high energy and minimum weight- and size indicators. In industrialized countries, the system “free piston engine – reciprocating electric generator of transverse type” is considered as a promising power plant.
The main feature of this kind of power plant is the lack of crank mechanism in the engine design. This allows: increasing the efficiency of the engine up to 50–60 % and overall power by 2.5–3 times while reducing the specific gravity and metal consumption compared to traditional engines; reducing the specific fuel consumption of the engine up to 30 %; increasing the resource to overhaul by 30–50 thousand hours; implementing a modular structure.
The main drawbacks of this kind of power plant are high probability of failure when passing the ignition of the working mixture and instability of work with significant load fluctuations. The noted drawbacks are due to the inconsistency of the forces of the electrical and mechanical subsystems of the power plant throughout the operating cycle. The solution for the problem of matching the forces of the electrical and mechanical subsystems of the power plant in the extreme positions of the piston group of the free piston engine is of particular complexity. In this regard, a method for solving the problem of matching the forces of the mechanical and electrical subsystems of the power plant with a free-piston engine throughout the operating cycle was developed, characterized by the use of an electromechanical reciprocating energy converter with transverse- and longitudinal nonlinear changes in the magnetic flux in the electrical subsystem. Coordination of the forces of mechanical and electrical subsystems of the power plant on the entire operating cycle makes it possible to fulfill the conditions of continuous electromechanical energy conversion at all work cycle and to reduce the specific gravity of the electrical subsystems of the plant while improving efficiency.

The paper discusses the results of a kinetic study of the pyrolysis of woody biomass (ordinary oak wood – Quercus robur) under static conditions at temperatures of 673, 773 and 873 K. In experiments, biomass samples weighing about 1.4 g were kept in a heating furnace for a certain period, after which their residual weight was measured and the degree of decomposition achieved was determined. A total of 7 series of experiments were performed: two series each at temperatures of 673 and 873 K and three series at a temperature of 773 K. The obtained results were analyzed in the framework of a single-stage chemical reaction (one-step global model), leading to a loss of the initial mass. It was established that from the phenomenological point of view, the pyrolysis of woody biomass under experimental conditions corresponds to the sigmoidal reaction model by Avarami–Erofeev with an exponent n ranging from 0.508 to 0.985. The use of the results of the first series of experiments led to an activation energy value of 57.2 kJ/mol and a pre-exponential factor value of 38 s^–1. The other series of experiments gave an activation energy value of 64.9 kJ/mol and a preexponential factor value of 130 s^–1. It is shown that the use of these values of the activation energy and the preexponential factor leads to agreement of the calculated values of the degree of decomposition of the studied biomass samples with the experimental ones in the range of values of the degree of decomposition from 0 to 1. The data presented in this work contribute to a more complete understanding of the kinetics of pyrolysis of biomass, which is necessary for the development of effective equipment for the thermochemical processing of vegetable raw materials.

Transmit diversity under transmission of signals from the base station to mobile station using the code-division multiple-access (CDMA) system allows us obtaining the performance gains close to the mobile station receiver diversity without complexity of the mobile station receiver antenna array. The multipath diversity can be achieved using the pre-RAKE precoding at the transmitter that could be employed and there is no need to install the RAKE receiver at the mobile station. We investigate several transmitter diversity techniques employed by wideband CDMA (W-CDMA) systems. We also study a possibility to combine transmitter diversity and precoding that achieves the gain of maximum ratio combining of all space and frequency diversity branches jointly with long-term prediction algorithm. It was demonstrated that the performance of the space-time pre-RAKE method approaches the performance of the maximum ratio combining for all space and frequency diversity branches. It is shown that all closed loop methods depend on the long range prediction to approximate the ideal performance in the fast fading environment.

The study of reliability indicators was carried out on the example of a cluster supercomputer configuration of “SKIF-GEO” (further cluster) worked out within the framework of the scientific and technical program “SKIF-Nedra” (2015–2018, Program of the Union State of Russia and Belarus). The cluster is a stationary supercomputer configuration designed to solve resource-intensive applications in data processing centers (DPC). Computing platforms and other cluster modules are located in the same 19′′ rack height of 42U. Theoretical peak performance of cluster – 100 Tflop/s. The basic architectural principles implemented in the cluster, the composition and structural-functional scheme of the cluster are given.
A methodological support for calculating the reliability of the cluster, based on previous studies by the authors, is proposed. Taking into account these studies, the structural scheme of reliability (SSR) of the cluster, consisting of two parts – the cluster core and the combination of computing facilities (nodes) (CCF), is substantiated. The component parts (CP) include components of the cluster, the failure of which leads to a decrease in performance to zero. CCF includes CP of cluster, the failures of which lead to a decrease in cluster performance. The choice of the main indicators of the reliability of the cluster core and CCF is grounded and formulas for calculating these indicators are given. The analysis of the consequences of failures of cluster components is made. Taking into account the analysis, the SSR of the cluster core is determined, which allows to derive a formula for calculating the cluster core reliability indicators. A mathematical model of reliability (state graph) of an CCF cluster is proposed, which allows one to derive formulas for calculating the mean time to failure and the mean time for a failure of the CCF of cluster.
An assessment of the reliability of CP cluster, for which there is no reliable information on their reliability, is determined based on the SSR of these CP. An assessment of the reliability of the cluster as a whole, based on the calculation of reliability indicators based on reference data on the reliability of components and components, as well as on data from the operation of supercomputers of family “SKIF” has been carried out. Taking into account this estimation and the calculated ratios obtained, the cluster reliability indicators for two options were calculated (in the presence and absence of a reserve of computing nodes).
High values of cluster reliability indicators were achieved due to the architectural and structural solutions adopted in the process of its development, aimed at increasing its survivability.

The aim of the article is to ground the probabilistic approach to the acceptance of expert decisions on examinations of difficult objects with the use of the information technologies conducted on the basis of the used methodologies of realization of examinations.
Criminalistics identification researches of difficult objects are conducted by comparison of the identification signs got from debatable (investigated) and exemplary (experimental) identifying objects. For comparison at first it is necessary to measure them, and already after it to compare inter se, i.e. to find the measure of closeness between the compared identification signs. And here are two aspects of estimation of authenticity of results of comparison.
First from them belongs to determination of probability of complete coincidence of parameters of identification signs of two different objects. In other words, it is the aspect of proof of strict individuality of descriptions of the investigated objects, confessed in the whole world and allowing to use the categorical form of formulation of conclusion of expert. The calculation of probability of coincidence of fingerprint cards of two different personalities belongs exactly to this aspect. The second aspect is related to probabilistic character of processes of both origin of identification signs in difficult objects and their selection, measuring and comparison during realization of criminalistics researches. Exactly he is related to the probabilistic going near the estimation of results of criminalistics researches of difficult objects.
It is shown that the result of any examination of difficult object, related to measuring of concrete sizes, is characterized by the presence of random constituent and its result must be presented in a probabilistic form. There are three separate random values determined by probability, characterizing examination and tool intended for identification researches of difficult objects At creation of tool for realization of examinations of difficult objects and its introduction into practice, the curves of values of probability errors of І and ІІ family must be made and its minimum efficiency must be determined. Exactl efficiency of tool must serve as a criterion for its suitability for realization of expert researches.

Scientific-technical aspects of technology of use of the ice wall when shaft sinking in water-bearing rocks, using an example of objects under construction of the Petrikov mining and processing plant, are studied. The algorithm of process of freezing of the mountain massif is described. The method is developed of calculation of the main parameters of the ice barrier, based on classical scientific concepts in the field of geotechnology, geomechanics and mountain thermal physics, containing modified formulas of thickness and time of the ice wall formation. The high efficiency of the developed technique is confirmed by the results of the successful use of the obtained numerical values of the parameters of the fence in the implementation of the project of sinking shafts. It is shown the possibility of choosing a method of defrosting frozen rocks, based on the analysis of a real three-dimensional model of the ice barrier. The most important criterion for this choice is the uniformity of the thickness of the ice barrier along the circumference of the vertical cylinder. The conclusion is made about the high scientific and practical competence of Belarusian mine builders – scientists and specialists. The country has developed a reliable system of scientific and technical support for the technology of sinking vertical mine shafts using temporary ice fences. Effective methods of preliminary geological studies, calculation of parameters of ice-rock fences and freezing equipment, selection of technology of work have been created. The necessary material and technical base for fast and high-quality performance of all complex of works on a construction of mine trunks in the special way is created.

The aim of the current work is to perform a probabilistic dose assessment to quantify the relative importance of the source data uncertainties contribution towards the uncertainty estimates of collective and maximum individual doses of personnel during decommissioning of a storage facility. A probabilistic approach to the analysis of dose loads, including the analysis of sensitivity and uncertainty with respect to the input parameters of the used calculation models of dose assessment, allows to determine the most sensitive parameters, inaccuracies in the task of which lead to significant uncertainties in the estimates of dose loads on personnel and, therefore, require more accurate determination of conservative boundary values in deterministic analysis and safety justification. The calculations were performed by applying the code RESRAD-BUILD 3.50, developed by the Argonne National Laboratory of the US Department of Energy. The obtained results allow us to rank the parameters of the computational model according to the degree of their influence on the uncertainty of the final estimates of the dose loads on personnel, to develop recommendations for optimizing dose loads when performing radiation-hazardous work during nuclear facilities decommissioning.