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Background and Objectives: In practice, there are often processes in which in the initial state the working medium is single-phase, for example, in the form of gas (steam), and during the process under study conditions are created for the appearance of a new phase in the form of droplets (nuclei). The process of nucleation and further condensation growth of clusters in supersaturated vapor is one of the most important processes leading to the development of the dispersed phase. The liquid phase nuclei that appear as a result of nucleation are quite small (nano-sized) and, therefore, subject to Brownian wander, which leads to their mutual collisions and coagulation. The processes of evaporation and condensation in various media are used to obtain nanomaterials (in particular, in the synthesis of carbon nanotubes), as well as to obtain nano- and ultradisperse particles in expanding channels due to nucleation and their condensation and coagulation growth. Materials and Methods: Using a quasi-equilibrium model based on the equations of mechanics of multiphase media, the flow of a dispersed mixture in a channel with sudden expansion in the presence of processes of nucleation, coagulation of nuclei (clusters) and phase transitions (evaporation, condensation) in a two-dimensional formulation was studied. The homogeneous nucleation model is used to describe the nucleation process. It is assumed that the process of coagulation of clusters occurs due to their Brownian motion. To determine the rate of phase transitions, the Hertz – Knudsen – Langmuir formula is used. The problem of the flow of a gas-dispersed mixture in a channel with sudden expansion in a twodimensional formulation is considered. It was assumed that in the narrow part of the channel, under certain conditions, nuclei of the dispersed phase continuously appear, which enterthewidened part ofthe channelwiththe flow. The calculationswere carried out based onthe algorithm of the numerical “large particles” method, which is based on splitting the original equations into physical processes. Results: As a result of the study, the basic properties of the flow of a two-phase mixture in a channel in the presence of nucleation, coagulation and phase transitions have been established. It has been shown that the flow has a vortex structure, and the largest particles are formed precisely in the vortex zone. Calculations have established that the coagulation process has a fairly strong effect on the distribution of cluster sizes inside the channel. The influence of the degree of steam supercooling on the flow of the dispersed mixture in the channel has been studied and it has been found that this parameter significantly affects the density distribution of the dispersed phase. The flow pattern obtained using calculations is consistent with experiment. Conclusion: The basic properties of the behavior of the mixture parameters along the expanding channel at presence of nucleation, coagulation and phase transitions have been established. The results obtained can be useful in various areas of modern technology: when designing various heat-power and heat-exchange installations, for studying the process of outflow of various mixtures from containers, for modeling the processes of formation and growth of nuclei (in particular, nanoclusters) in saturated media, etc.

Purpose: hydraulic calculations of the current water supply network of the Chernozemelskaya irrigation system channels. Materials and methods. The materials for the calculations were: operational records of the Chernozemelskaya irrigation system, the results of field surveys of channels and data from instrumental measurements of water levels, velocities and water discharges in the surveyed discharge section lines of distributary channels. The field work was carried out according to the generally accepted rules and methods of surveys, hydrometric measurements and assessment of the reclamation facilities state. Channel hydraulic calculations were performed for the conditions of constant water flow in their channels on rectilinear sections. Calculations of the main elements of the water cross-section of the Chernozemelskaya irrigation system channels were carried out using passport data and the results of field surveys of these channels. Results. Calculations of the main elements of the water cross-section of the channels for the control stations on the Yashkul and Gashun distribution canals of the Chernozemelskaya irrigation system were performed, rating curves of discharge and average water flow velocity in channels from the depth of their filling were constructed; permissible (non-eroding and non-silting) velocities of water flow in the channels were determined. Conclusions. It was found for the discharge section line on the Gashun distribution canal, that siltation of the channel will occur at a water flow discharge of Q < 2.75 m³/s and channel filling of h < 1.0 m. When assessing the channel of the Gashun canal for the susceptibility to erosion, it was determined that the channel in the control station section can pass the specified discharge without being eroded. Checking the channel of the Yashkul distribution canal in the control section for siltation and erosion showed that its channel will not be eroded in the considered range of water flow velocities from 0.62–1.14 m/s.

The work is devoted to an experimental study of the behavior of bubbles when capturing pulverized materials with nanoparticles in the course of colliding of gas-liquid jets in a bubbling layer. The article discusses the use of channels in a jet bubbler and the dependence for detecting horizontal movement of bubbles with nanoparticles in them. The purpose of this stage of research is to study the behavior of gas-liquid jets when exiting without a guide channel and through a guide channel. The results of experiments conducted on the patented design of the jet bubbler are analyzed. The article presents the results of experiments conducted to study the shapes and sizes of formed gas bubbles. The graphs constructed after processing the frames of the kinogram according to the data of the experiments are given. On the basis of preliminary tests, the features of using channels to create the jet collisions in an experimental setup to increase the range of captured solid particles, including nanoparticles, are substantiated.

The optimal operating modes are determined for channel sections based on the condition that all lateral water intakes are guaranteed to receive the planned flow rates of water resources with minimal filtration and evaporation water losses. Lateral outlets are guaranteed to receive water flows if they have appropriate heads of water in front of the facility. These necessary heads determine the values of water levels in the channel sections, which are determined in the process of water distribution. In the process of operational management of water resources in mechanical water-lifting systems, established water distribution limits are implemented, taking into account the current actual situation with the availability of water resources and the technical characteristics of pumping stations and hydrotechnical structures of the irrigation system, as well as the technical characteristics of hydrotechnical structures and canal sections of the entire irrigation system. Currently, optimal management of water resources is carried out with the help of a dispatch service, and the operating modes of canal sections are determined by dispatchers. Therefore, significant deviations of actual regimes from planned values, unevenness and instability of water supply to consumers are constantly observed. Based on the above, the article developed mathematical models of the unsteady flow of water resources in the section of the main canal and seasonal reservoir based on the nonlinear differential equations of Saint-Venant. An algorithmic sequence for determining the operating modes of a hydraulic structure is also given, with the help of which it is possible to manage the water resources of the main canal, which will satisfy the needs of water users with minimal losses of water and energy resources.

Objective. Mathematical modeling of heat transfer in pipes with turbulators for viscous heat carriers at Reynolds numbers characteristic of laminar and transient flow regimes is carried out by the calculation method. The solution of the heat exchange problem for semicircular cross-section flow turbulators based on multiblock computing technologies based on the solution of the Reynolds equations (closed for the transient mode using the Menter shear stress transfer model) and the energy equation (on multi-scale intersecting structured grids) by the factorized finite-volume method (FCOM) was considered.Method. The calculation was carried out on the basis of a theoretical method based on the solution of the Reynolds equations, closed for transient modes using the Menter shear stress transfer model, and the energy equation on multiscale intersecting structured grids (FCOM), by a factorized finite-volume method.Result. Both local and averaged characteristics of the flow and heat exchange in pipes with turbulators for a viscous coolant for laminar and transient flow modes of the coolant were obtained using the FCOM method in the work, which made it possible to determine for these modes the levels of heat exchange intensification that satisfactorily correlate with the existing experiment.Conclusion. The calculated relative hydraulic resistance for low turbulators increases quite slightly, and for medium-altitude turbulators reaches 2÷2.5 to the critical Reynolds number, and subsequently it increases up to 3 times; for high turbulators, the relative hydraulic resistance increases up to 4 times even before the transition flow regime is reached, after which it increases up to 4.5 times. The calculated relative isothermal intensified heat exchange under the laminar flow regime of a viscous coolant for relatively high turbulators increases almost 2 times; for relatively medium heights of turbulators — almost one and a half, and for low relative heights, the intensification of heat exchange is insignificant.

The urgency of brash ice study is growing in connection with intensive shipping in fast ice zone of freezing seas as well as inland waterways. In addition, an important incentive for such studies is the design and construction of port infrastructure in these water areas. The review shows that the main directions of research refer to three main topics. 1) Investigation of morphometrical brash ice characteristics in navigable channels and harbors, their variability under ambient factors. The most well-studied morphometrical parameters of brash ice are relative channel thickness and its distribution over channel width. Size distribution details about brash ice floes are of great interest for researchers. 2) Investigation of porosity and mechanical properties of brash ice as a granular material taking account of freezing between individual ice blocks. In many respects, these parameters determine the pattern of brash ice interaction with ships and the possibility of their movement. 3) Description of consolidated layer formation in brash ice and refinement of predictions for brash ice growth in the water area under consideration depending on the intensity of ship traffic and the number of degree-days with negative temperatures over the time interval between ship passages. Large attention is given to new methods of studies including full-scale and laboratory experiments, as well as the use of ice basins for this purpose, with a brief review of thermal methods for brash ice management. The paper formulates some of the problems yet to solved, which require extra studies.

A new type of gold mineralization has been revealed in rocks of the basement of the Aldan-Stanovoi gold-bearing province, within the Spokoininsky ore cluster of the Tyrkandinsky gold-bearing region of southern Yakutia. A geological model has been created of an object with a bulk-minable nonlinear type gold mineralization related to elements of plicative structures and to the reverse fault type tectonics in the hosting metamorphic rocks of the basement. The modeled object is represented by a combination of lodes with veinlet-disseminated sulfide-(pyrite)-quartz mineralization. A complex has been refined of prospecting guides and criteria, that characterizes this mineralization type represented by the ore-bearing lodes with gold-quartz and gold-low-sulfide-quartz veinlet-disseminated mineralization in rocks of the basement and Late Jurassic-Early Cretaceous magmatic formations. The structural-geological position, the morphological type, the composition of the ore-hosting rocks and ores, and the principal parametric characteristics of the gold mineralization have been determined. Sampled intervals with the gold grades corresponding to the required parameters for the preliminary estimation have been distinguished in the exploration workings. Forecasted resources of the P2 category have been assessed.

When studying medieval cities, along with the complex issues, including the structure, defense system, localization of cities according to written sources, identifying economic districts, is the study of the ancient irrigation system. Although the city of Syganak is mentioned in Arabic and Persian sources of the 10th century, we can find data on the irrigation system of the city in the work of the 16th century “Mikhman-name-iy” by Bukhara Fazlallah ibn Ruzbikhan. The waqf letters discovered by V.V. Bartold mention rivers near the city of Syganak and canals drawn from the Syrdarya. Data on the irrigation of Syganak are contained in the “Book of the Big Drawing”, “Drawing Book of Siberia” by S. Remezov. In Soviet times, E.I. Ageeva and G.I. Patsevich, V.N. Groshev drew attention to the issues of the irrigation system of Syganak. S. Zholdasbaev, who studied the city of Syganak for many years, paid special attention to the origin of the name of the canal Tuman aryk, derived from the Syr Darya. In this article, the authors drew attention to a controversial issue related to the location of the medieval city of Syganak. In some sources, the city is located on the right bank, in others – on the left bank of the Syrdarya River. Some researchers, relying on these sources, suggest that another city, Syganak, is mentioned in written sources. Our field studies have shown that the Syr Darya had several old channels in the vicinity of the city of Syganak. The discovery of these channels confirms that at one time the city was located on the left bank of the Syr Darya. The Sarysu and Shu rivers from Central Kazakhstan and Semirechye at the northwestern end of Karatau flowed into these old channels. Also, in the course of research along the ancient canals, several medieval cities and settlements of the cities of the Syr Darya were identified. The article provides information about ditches, derived from the Syr Darya, also provides data on the rivers originating in the southern part of Karatau, about their ancient names. The authors reveal that the toponymic names of Kyrash, Toktamys, Kelte-Shalkiya, Arystandy, Mynbulak found in vakuf charters have retained their names to this day.

Objective. The aim of the study was to determine the dependence of the distributions of average integral hydraulic resistances and convective heat transfer in turbulent flow in pipes with small (short channel) and large (long channel) sequences of semicircular periodic protrusions based on numerical solutions of the Reynolds equation systems, closed using Menter's shear stress transfer models, and energy equations on a multi-scale intersecting structured grid.Method. The calculation technique based on finite volume solutions of the Reynolds equation, closed using the Menter shear stress transfer model and the energy equation on a multi-scale intersecting structured grid, made it possible, with acceptable errors, to calculate the average coefficients of hydraulic resistance and heat transfer in a pipe with different quantities annular semicircular ledges.Result. Analytical comparisons were made of the calculated ratios for relative heat transfer and hydraulic resistance on the number of protrusions in channels with different values of relative heights of turbulators h/D, relative steps between turbulators t/D, different values of the Reynolds criteria Re, with other equivalent parameters, which showed that in in which case the qualitative deviations of the above characteristics are carried out monotonously, and in which case they are accompanied by extrema or inflections, and also showed cases of qualitative changes in the calculated characteristics. With the transition from 30 protrusions to 50, as a rule, only quantitative differences occur for the relative parameters of hydraulic resistance and heat transfer, and their qualitative changes are insignificant; with a further transition from 50 protrusions to 100, their quantitative changes also become insignificant.Conclusion. The nature of the patterns of distributions of the mean integral characteristics of flows and heat transfer for a channel with protrusions of various numbers must be taken into account for a short channel. An analysis of the calculated information obtained showed that when moving from a short channel with turbulators to a long one, most often, there is an increase in relative heat transfer and a decrease in relative hydraulic resistance, which justifies the advantage, from the point of view of intensification, of heat transfer by turbulence of the flow of the last channels in relation to the first channels.

The study considers the solution of a number of problems of supersonic and hypersonic gas dynamics using a model that takes into account the dissociation and ionization of air. The results of verification and validation of the developed numerical method using various difference schemes (the Roe scheme, Rusanov scheme, AUSM scheme) for discretizing convective flows are presented. The formulation of the mathematical model for high-temperature air uses the presence of equilibrium chemical reactions of dissociation and ionization. For this purpose, at high incoming flow velocities, the Kraiko model is applied, which includes equilibrium chemical reactions in air at high temperatures. To discretize the basic equations, the finite volume method on an unstructured grid is applied. One of the features of the constructed mathematical model is the implementation of the transition between physical and conservative variables. Relationships are given, with the help of which the transition from conservative variables to physical ones and vice versa is carried out when using the high-temperature air model. To ensure the stability of numerical calculations, an entropy correction is introduced. The decrease in entropy in the solution of hyperbolic equations is excluded by introducing an artificial viscosity according to Neumann, as well as by using the Godunov method with an exact solution of the Riemann problem and methods based on the approximate solution of the problem of the decay of an arbitrary discontinuity. A number of problems of supersonic gas dynamics (supersonic flow in a channel with a straight step and supersonic flow around a sphere) are numerically solved taking into account high-temperature effects. The criteria for the accuracy of numerical calculations related to the location of shock-wave structures are discussed. The calculated shock-wave structure of the flow is compared with the data available in the literature, as well as with calculations using the perfect gas model. Some results of numerical calculations are compared with the available experimental data. The shock-wave flow patterns obtained in the framework of the inviscid model, which takes into account the effect of viscosity and its dependence on temperature, and the turbulent flow model are compared. On the basis of numerical simulation data, the influence of viscous effects on the flow characteristics in a channel with a straight step and hypersonic flow around a sphere is considered. The influence of various numerical factors on the shape of the bow shock and the presence of fluctuations in the solution behind the shock is emphasized. As part of the work, a computational module was prepared for the commercial package Ansys Fluent, implemented with the help of user programming tools. The prepared module expands the standard capabilities of commercial software focused on solving computational gas dynamics problems, and is available to Ansys Fluent users for solving hypersonic aerodynamics problems. The developed means of numerical simulation can be useful in the design and optimization of hypersonic aircraft.

The relevance of the study is conditioned by the necessity of achieving an uninterrupted and reliable operation of systems associated with the transportation of georesources. An important component of the engineering structures of these systems are bridge crossings. On the streams of the mountain zone, these crossings are often performed single-span. In the transition sections for establishing the bridge supports, the width of the river narrows, which leads to erosion of the bottom soil. The mark of the sole of the support and the very conditions of its long-term operation, depends on the accuracy of determining the maximum amount of erosion of the bottom of the river. From this point of view the problem under consideration is topical and will follow a solution that is of important practical value. The main aim of the work is modelling of channel transformations processes running at bridge crossing sections in mountain foothill zones and developing a calculation method for determining riverbeds deformations. The objects of the present study are initial parameters of the stream and channel characteristics of waterways in mountain foothill zones, hydrodynamic processes occurring at the bridge crossing section in rivers of a mountain foothill zone; channel deformations of the bottom; boundary conditions of the problem and the shape of the cross section of the channel. Methods. As a result of a relatively complete analysis of existing works the current state of the set problem has been assessed and the ways of development were marked; physical and theoretical modeling of the channel transformation at the bridge crossing area was performed; boundary conditions for various structural solutions of bridge crossings were determined; a method for hydraulic calculation of channel transformations at bridge crossings was developed for streams of mountain-foothills; numerical example was calculated according to the developed methods and the obtained results were analysed. Results. The paper introduces the physical model of the final stable stage of channel transformations at the bridge crossing section. The hydrological, hydraulic and channel parameters that are initial in solving the problem are identified. A mathematical model of nonuniform flow motion in the conditions of the transformed river bottom of the transition section was compiled taking into consideration equations of energy, continuity of flow and sediment balance. At the same time, the problem in view is aimed at establishing such a position of the bridge crossing bottom when the channel erosion will come to the end and the steady-state flow – restored. In elaborations boundary and boundary conditions of the problem were established. Dependences of the transverse form of the channel and the Shezy formula were also used. As a result of joint solutions of the above expressions a calculation method was developed to establish the position of the stabilized bottom on the transitional section of the river and hydraulic parameters of the flow. A numerical example of calculation made for determining the coordinates of the stabilized bottom and free surface in a bridge crossing is presented. The estimation of calculation results is given. The authors have made a conclusion on possibility of using the proposed method in calculations of parameters of transitional sections of mountain-foothill rivers.

Subject of Research. Numerical simulation of a shock wave propagation in a plane curved channel is considered on the basis of numerical simulation data. Method. Calculations of an inviscid compressible gas were carried out on the basis of unsteady two-dimensional Euler equations. Discretization of the basic equations was carried out using the finite volume method. Calculations were carried out for different channels with different radius of curvature and Mach numbers of the initial wave. To find the angular position of the front at the current time, the absolute value of the derivative of the density with respect to the angular coordinate was used. The calculation results were compared with the data of a physical experiment. Main Results. The features of the emerging shock-wave flow pattern and its development in time are discussed. The shock-wave configuration observed in channels with different radii of curvature is compared. Some differences in the curvature change of the front of shock waves formed in channels with different radius of curvature are shown. The size of the Mach leg and its change with time depending on the intensity of the initial wave and the size of the annular gap is the angular coordinate function corresponding to the position of the shock wave at the current time. While the maximum Mach number on the outer wall is relatively weakly dependent on the initial wave velocity, the Mach number on the bottom wall decreases with increasing Mach number at the channel entrance. The performed numerical studies show that in all variants there are no non-physical oscillations of the solution. Practical Relevance. The study of shock-wave and detonation processes is of interest for using their potential in pulsed installations and power systems for aircraft and rockets. The calculation results are important for the search of the new flow patterns that guarantee the formation of self-sustained detonation combustion in the combustion chambers of promising propulsion systems. Adjusting the size of the annular gap gives the possibility to select a geometric configuration that will provide the formation of an optimal triple shock wave structure, as well as the required intensity and size of the Mach wave.

The relevance of the study is caused by the need to ensure the point distribution of acid solution during acid treatment of the bottomhole zone of the production well. Using this method, the efficiency of this process increases by deeper dissolution of limestone rock in the bottomhole zone of the well and thereby completely opening channels for the flow of formation fluid from the formation into the well. The aim of the research is to develop and propose a method of point hydrosand-jet perforation during acid treatment of the bottomhole zone of a production well, a methodology for its application, and to create designs for underground and surface equipment of wells for implementing the developed method. Objects: laboratory stand with a device simulating a channel in the rock; hydrosand-jet perforator for hydrosand-jet opening; clamp designed to prevent breakage and relieve tensile stresses in the pipe string during hydrosand-jet opening and for fixing when centering the perforator in a given processing interval; acid solution based on hydrochloric acid with a volume of 3–4 m3; displacement fluid. Methods. The experimental study of the pressure in the channel at point hydrosand-jet perforation was carried out on a stand. In the device, a nozzle and a fitting of certain diameters – d and D – were installed at the required distance between them. The pumping unit was used to pump the liquid at a pressure p1 before the attachment, and the pressure inside the branch pipe p2 was recorded. In the experiments, water and aqueous solution of sulfite-alcohol stillage with a viscosity of 12,65 cPz at 20 °C were used as the working fluid. The selective acidizing consists in the fact that a hydroseed-jet perforator is lowered into the well, set at the level of the selected treatment interval, and hydraulic clamps necessary to strictly hold the perforator. After that 3–4 m3 of acid solution and squeezing fluid are pumped in. Then, air or gas is injected into the tubing and the annular space (up to the maximum pressure in the distribution booth) and in this state the well is left under pressure for 20 hours and at the end the well is drained to extract the reaction products to the surface. Results. From the analysis of the results of multiple (threefold) hydro-acid treatment, it can be seen that the initial injection pressure of the acid solution after the first stage of the well treatment was reduced by 24 %, and after the second – by 55 %. The acidizing method with additional accurate perforation of the bottomhole zone of production wells allows implementing a more efficient treatment. As a result, the volume of formation fluid inflow from the formation into the well increases by 20...30 % in comparison with conventional acidizing.

Relevance. Asymmetry of the drawing channel during processing and destruction of the drawing in the process of drawing.Purpose. To determine the effect of the parameter of roughness of the landing hole of frames on the quality of manufacturing of lugsThe results of the study. The influence of the roughness parameter of the bore rims on manufacturing quality dies was defined.

Objectives. The aim is to study the dependency of the distribution of integral heat transfer during turbulent convective heat transfer in a pipe with a sequence of periodic protrusions of semicircular geometry on the Prandtl number using the calculation method based on a numerical solution of the system of Reynolds equations closed using the Menter’s shear stress transport model and the energy equation on different-sized intersecting structured grids.Method. A calculation was carried out on the basis of a theoretical method based on the solution of the Reynolds equations by factored finite-volume method closed with the help of the Menter shear stress transport model, as well as the energy equation on different-scaled intersecting structured grids (fast composite mesh method (FCOM)).Results. The calculations performed in the work showed that with an increase in the Prandtl number at small Reynolds numbers, there is an initial noticeable increase in the relative heat transfer. With additional increase in the Prandtl number, the relative heat transfer changes less: for small steps, it increases; for median steps it is almost stabilised, while for large steps it declines insignificantly. At large Reynolds numbers, the relative heat transfer decreases with an increase in the Prandtl number followed by its further stabilisation.Conclusion. The study analyses the calculated dependencies of the relative heat transfer on the Pr Prandtl number for various values of the relative h/D height of the turbulator, the relative t/D pitch between the turbulators and for various values of the Re Reynolds number. Qualitative and quantitative changes in calculated parameters are described all other things being equal. The analytical substantiation of the obtained calculation laws is that the height of the turbuliser is less for small Reynolds numbers, while for large Reynolds numbers, it is less than the height of the wall layer. Consequently, only the core of the flow is turbulised, which results in an increase in hydroresistance and a decrease in heat transfer. In the work on the basis of limited calculation material, a tangible decrease in the level of heat transfer intensification for small Prandtl numbers is theoretically confirmed. The obtained results of intensified heat transfer in the region of low Prandtl numbers substantiate the promising development of research in this direction. The theoretical data obtained in the work have determined the laws of relative heat transfer across a wide range of Prandtl numbers, including in those areas where experimental material does not currently exist.

Technical measurements of linear-angular sizes of parts and products are the most common in mechanical engineering and make up to 95% of the measurements of all controlled sizes. Measuring control is an integral part of each operation of technological processes of production, assembly, testing of products. The complex method of measuring the external and internal geometric characteristics of a carbide die, given in the article, allows to measure the geometric parameters of small-size parts and to give a final assessment of the product for compliance with the requirements of the project technical documentation.

The Eurasian integration processes play a significant role in the development of marketing strategy aimed at improving the competitiveness of television services on the television market through cooperation with other companies, which contributes to the formation of competitive advantages of both sides. The expansion of the interstate cooperation due to the interaction of different mass media raises the efficiency of integration processes.

Communication networks are complex information systems influenced by a vast amount of factors. It is critically important to forecast the paths that data take to verify the network, check its security and plan its updates. Model allows exploring processes that take place in the network without affecting performance and availability of a real network itself. With modelling it becomes possible to investigate the results of infrastructural changes introduced to the network before actually implementing them. It is important to be able to formally convert real network description into the model definition which preserves all data that is significant for network operation and skip data which is not. Outlining the rules for such conversion and using a limited set of basic functional components provide the ground for automatic model creation for the network of different levels of complexity. Proposed approach to modelling of communication networks is based on decomposition of the overall function of every particular real network component into a set of functions that belong to some predefined basic set. Functions of the basic set include L3 routing, L2 switching, packet filtering, NAT, etc. Model of a real network component is defined as a group of functional nodes each of which implements some function from the basic set. Configuration and current state of network components that influence its operation are also decomposed into elements each of which relates to some particular functional node. Configuration of network components is modelled as a set of configuration storage elements and current state is modelled as a set of current state storage elements. Links that connect real network components and links that connect functional nodes in the model are presented as single-direction channels that implement propagation of L2 frames thus simplifying the model due to excluding physical layer (L1) from the scope. Using the proposed approach to modelling may allow to formalize conversion of a real network description to a model thus making automated modelling possible. By using a sufficient basic set of functional nodes it is possible to model the network containing components of any complexity level. [ABSTRACT FROM AUTHOR]

Exchange of Bivalvia and Gastropoda larvae between the Aniva Bay and Busse Lagoon is described on results of the plankton survey conducted in the connecting Suslov Channel in 2014. Taxonomic composition of meroplankton is described. Tide-induced water exchange through the channel is estimated, as well. The total water flux is evaluated for each tidal cycle using the data on the water level in the lagoon and on the area of its water mirror. The main factor of the larvae exchange is the tidal water flow that reaches the rate of 4 knots both for ebb and tide currents. The meroplankton from the lagoon is transported by the ebb current rather far to the sea, and its reverse drift with the tide current back to the lagoon looks doubtful, so export of the meroplankton from the lagoon is detected, with certain seasonal dynamics. The export is the most intensive in early summer (July) because of earlier spawning in the lagoon, which water is warmed quicker on shallows. The exchange decreases in August, when the water temperature is the highest both in the lagoon and in the Aniva Bay and many species spawn actively in both areas. Both reverse transport and export of the larvae are low in September because of the water cooling and cessation of the spawning.

The quality of the drawing tool depends on the quality of the channel. Channel processing is carried out in order to obtain the desired geometric shape, required size and limit deviations in accordance with the size and quality of the wire stretched, as well as to obtain the required purity of the surface of the channel drawing. The determination of the surface roughness in the die channel is not possible due to the design of the die, so the quality control of the channel polishing is carried out by a visual method using a stereoscopic microscope.In the laboratories at the Central laboratory of OJSC «BSW – Management Company of Holding «BMC» the experience was undertaken for the determination of the roughness parameter in the channel of the dies by the method of destructive testing. The results obtained show that the visual method of quality control of the working channel polishing of the carbide drawing tool with the help of a stereoscopic microscope provides sufficient accuracy of assessing the quality of the roughness of the surface of the working channel when monitoring the draw die intended for coarse-medium and thin drawing.

The results of the numerical analysis of thermal regimes and heat loss of the two-channel underground heating networks with using the convective-conductive model of heat transfer are presented. The two-dimensional coupled stationary problem of convective-conductive heat transfer in the system «underground two -channel heat pipeline - environment» is solved. The solution of the problem was obtained by the finite element method with using an uneven finite-element grid. The scales of heat loss and the patterns of heat transfer in the zones of underground two-channel heating networks are established. The possibility of analyzing the heat loss of two-channel heating networks with using of the model and the methodology for calculating the heat loss for single-channel heating networks is shown.

The authors provide a model that allows estimating the time of the break of functioning navigation and ATC that make up the information channel.

In modern ani-theft systems they use frequency and phase modulation. Since the width of the signal is limited, it is possible to intercept the signal and then switch off the alarm at the right time.To ensure the noise immunity and secrecy manufacturers use more sophisticated codes using the methods of cryptography. Significant increase in noise immunity in modern ani-theft systems is possible using broadband signals.

In this article the dynamical stability of elastic walls of plane channels under flowing of the perfect liquid is investigated on the basis of mathematical models. Either the law of pressure change or the potential of liquid velocity or the longitudinal component of liquid velocity are applied on the input and output from the channels. The sufficient conditions of stability are obtained. These conditions impose a constraint on the velocity of the liquid homogeneous stream, on the compressing (decompressing) force and other parameters of mechanical system.

Results of theoretical research movement of a liquid in channels cooling system of the engine are presented. The equations movement of a liquid in channels with a various arrangement are received. The questions, concerning changes energy of stream of a liquid in a liquid contour cooling system are considered.

Subject of research: In recent domestic practice of hydrotechnical, transport and environment-oriented construction, a semi-synthetic material — Enkamat A20 geomat (Enkamat) — has been widely used in recent years. The carpet from the geomat, filled with crushed stone with bituminous binding material, is used in the constructions of drainage structures and culverts to protect various types of soils (sandy, loamy and clay), as well as to prevent the destructive erosivity of the flowing water on the protected surfaces. The studying of the influence of the hydrodynamic effect of the water flow and the estimation of presence and absence of tearaway loads caused by a shift of flow pressure phases on the upper and lower geomat surfaces became the subject of the researches that were carried out. Objectives: the research program was focused on the quantitative and qualitative assessment of the hydrodynamic effect of the flow passing through the experimental stretch of the conveying channel for the condition and stability of the protective blanket of Enkamat А20 geosynthetic material. Materials and techniques: a series of physical experiments was performed, which made it possible to estimate the effect of the water flow on geosynthetic material. The results of the experimental measurements were processed and analyzed with the use of modern software. Results: in the process of the performed researches, the values of the flow pressure pulsations on the slope and the bottom of the conveying channel were determined at several values of the passing water flow rate, as well as the values water flow pressure pulsations under the protective geosynthetic blanket were determined. Findings: on the basis of the physical experiment, the differences in flow pressures on the surface of the geomat blanket — the upper surface that is in contact with the water flow, and on the lower surface that is in contact with the soil were obtained. The absence of tearaway loads on the lower surface of the blanket, which is in contact with the soil, was identified. Possible demonstrations of tearaway loads associated with the shift of water flow pressure phases on the upper and lower geomat surfaces are shown.

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