Red blood cells (RBC) roll like tractor caterpillars along narrow capillaries. On the erythrocyte surface there are charges that, when moving together with the erythrocyte membrane, create a magnetic field in the vicinity of the RBC. Discrete charges are distributed uniformly on the surface of the RBC, their number can reach several million and the charges move together with the RBC membrane. The surface of the RBC is approximated by a truncated cylinder. Discrete charges are located evenly over the surface of the RBC and move along closed curves that are rectangular trapezoids. A mathematical model has been constructed that allows calculating the intensity of the magnetic field produced by mobile charges located on the RBC membrane. According to the Bio-Savart law, the magnetic field strength can be calculated at some point in space if the coordinates and velocity of the charge are known, the distance from the charge to the point and the angle between the velocity vector and the radius vector connecting the charge and the point. If we assume in the first approximation that the medium is isotropic and magnetic currents are absent, then Maxwell's equations can be written out. These equations can be rewritten in the form of equations in finite differences, solving by numerical methods one can obtain distributions of electric and magnetic field strengths in the vicinity of the RBC. Calculations were carried out for different values of input parameters. In the case when the RBCs move through the capillary network, in which the narrow capillaries are located close to each other, the magnetic fields of the RBCs in different capillaries interact, and, as a result, we obtain a new distribution of the magnetic field strength in the vicinity of the capillary network, which varies with time.

Keywords: mathematical model, algorithm, magnetic field strength, electromagnetic interaction, erythrocyte, narrow capillary

The article demonstrates a computer model of a fiber-optic sensor implemented on the basis of a two-frequency optoelectronic generator (OEG) for measuring lateral pressure. In the loop of the optoelectronic generator, a fiber Bragg grating (FBG) with a phase shift is applied to which a transverse pressure is applied to guide the birefringence and create two orthogonally polarized transparency windows, which leads to the generation of two optical frequencies. The difference frequency of the beats between the two optical frequencies lies in the microwave range and depends on the magnitude of the pressure applied to the FBG. It was modeled that the sensitivity and the minimum detectable pressure are ~ 10 GHz / (N / mm) and 2.5 × 104 (N / mm), respectively. The high frequency and stability of the generated microwave component of the optoelectronic generator provide an extremely reliable and highly accurate measurement. Frequency survey allows the system to operate at high speed. In addition, the measurements are insensitive to changes in the ambient temperature and the wavelength of the optical carrier.

Keywords: transverse pressure, fiber optic sensor, fiber Bragg grating with phase shift, birefringence, optoelectronic generator, two-frequency optical signal with microwave frequency difference frequency

The results of the study of the stability of the core structure of a polygonal ring under the action of a system of self-balanced radial forces are presented. A complete solution of the problem is given in accordance with the fundamental equations of the theory of R. Mises as applied to a statically definable planar structure. It is established that the instability parameter of the core structure of the hexagonal ring is determined solely by the number of nodal points of the hinged rod system.

Keywords: core structure, regular polygon, hyperboloid, annular diaphragm, determinant, characteristic polynomial, cyclic symmetry

The present article is devoted to development and a research of the distributed fiber systems of aero acoustic control of parameters of an air-gas stream on a cut of a nozzle of turbomachines. The main emphasis is placed on development and to a research of the distributed fiber systems on the basis of control methods the using multiplexed fiber-optical sensors of control of parameters of an air-gas stream on a cut of a nozzle of the turbomachines using advantages of optical methods of information transfer and the device for his realization. The principles of creation of the complex systems of aero acoustic cartography complemented with methods and measuring instruments of gasdynamic parameters of a stream in a flowing part and on a cut of a nozzle of the turbomachines directed to increase in informational content and level of algorithmization of nondestructive control of a condition of working shovels and providing data acquisition in the conditions of parametrical and structural uncertainty of an air-gas stream as on controlled internal sections of a flowing part, and on output section on a turbomachine cut are defined. Problems of placement of points of control and restoration of spatial distribution of the field of measurements in discrete set of points separately are considered. Restoration of the acoustic field of turbomachines is implemented according to measurements at the exit of WATERS, only using statistical approach. Restoration of the field is presented in the form of continuous functions of spatial coordinates by results of measurement in discrete set of points in the presence of aprioristic information on properties of the measured fields. Statistical approaches for determination of coordinates of sensors and an error of restoration on the example of one model problem of control of the field of the radiation created by the continuous exclusive radiator are used. Results of calculations show that existence of correlation between coefficients of decomposition of the field of radiation on functions, leads to reduction, necessary for achievement of the set accuracy of restoration of number of sensors.

Keywords: distributed fiber systems, аero acoustic control, acoustic field, process simulation, recovery

The article provides a solution a schedule generation problem for the timber transportation, a description of the problem is given, and a multi-criteria mathematical model is created. It is indicated that the task in question can be assigned to the class of vehicle routing problems in the general formulation of GVRP related to the job-shop scheduling. A hybrid algorithm for solving the problem based on the decomposition method using the simplex method and the genetic algorithm was developed. Conducted testing showed the effectiveness of the developed method on real data of wood harvesting enterprises. The results of numerical methods testing on real data suggest a reduction of the complexes of forest transport machines downtime, and an increase of transported wood volume during the planning period. The scientific results presented in the article were used in the development of a planning and management system «Opti-Wood» developed by Opti-Soft company.

Keywords: wood harvesting, GVRP, optimization, job shop scheduling, operational logistics, genetic algorithm

Modern distributed temperature control systems are used today everywhere, in particular, in the telemetry of oil and gas wells. Thus, when creating a distributed fiber-optic temperature sensor based on Raman scattering (DTS) for these purposes, the problem of improving its metrological characteristics always remains urgent. They are in turn determined by the known SNR (signal-to-noise ratio, SNR from English Signal-to-Noise Ratio). To achieve this goal, it is proposed to use a promising method of increasing the SNR in the DTS based on encoding the probing sensor signal by the Hadamard code sequences (simplex coding). For this purpose, a numerical experiment is carried out to implement this coding method using the DTS model and taking into account the noise of the photodetector device. The article presents the simulation results, confirms the effectiveness of the coding method, and summarizes the results of the simulation.

Keywords: distributed fiber optic temperature sensor, Raman scattering, photodetector device, noise, signal-to-noise ratio, optical pulse encoding, Hadamard code, simplex coding

The article deals with the problem of optimal control of the train (OKT) from the standpoint of the modern theory of automatic control. This problem is relevant for many years, but to date it has not been completely solved, due to the large number of random factors affecting the nature of the train, as well as the development in recent years of high-speed and high-speed, as well as heavy and long-range traffic. The mathematical model of train movement and formulation of the OKT problem are presented, the classification of known methods of its solution is offered. A simulation model in Matlab/Simulink environment is developed, which allows to study different models and control laws. A metaheuristic algorithm for optimization of train operating modes using a simulation model implemented in the form of a software module in Matlab is proposed. The results of computational experiments confirming the convergence of the algorithm are presented.

Keywords: optimal control, autodriving, mathematical model, simulation model, metaheuristic algorithm

To date, the construction of the new techniques of construction of buildings and structures, as well as the most advanced durable and lightweight materials with high performance characteristics. All this allows you to build cost-effective, high-quality and aesthetically attractive houses. Depending on the materials used in the construction of multi-storey buildings was considered the effectiveness of ribbed coffered floors. Calculation of the 18-storey monolithic building was made in the program complex "Lira-CAD-2013". Floor slab typical floor is considered in the following schemes: buildings with a step of columns 6m and 12 m, the ceiling is flat and coffered with a 200mm plate 50mm, different beam cross-sections (200х400мм and 200х450мм), step 900х900 mm. analysis of the results showed that the most advantageous use of coffered ceilings in the building with a column grid of 12 m, with the use of high-strength concrete and reinforcement steel class A500.

Keywords: caisson ceiling, slab, beam, reinforcement, concrete, analysis, consumption, reinforcement, step columns, the cost of construction, structural scheme

In this paper, it is shown that the noise of the photodetector device (PD) is the dominant factor limiting the metrological characteristics in real distributed fiber-optic temperature sensors based on Raman scattering (RDTS), which contribute significantly to the process of signal noise using the example of the RDTS taking into account the noise of the PD, which was chosen as the avalanche photodiode (APD). The analysis of the main types of noise in the model of an APD in the model, including both basic PD noise, and characteristic for APDs, for example, their influence on the signal-to-noise ratio (SNR). The graphs of the dependence of the influence of noise on the RDTS, derived from the SNR ratio, are given and conclusions are drawn about the predominance of some noise over others under different conditions, based on their.

Keywords: distributed fiber optic temperature sensor, avalanche photodiode, shot noise, dark noise, thermal noise, amplitude noise, signal-noise ratio, random number distribution law

The article discusses the process of sulfuric acid alkylation used to produce high-octane gasoline, as well as the design of jet reactors, their advantages and disadvantages. Based on the existing drawbacks of jet reactors, the development of a new high-efficiency jet reactor design has been proposed.

Keywords: reactor, sulfuric acid alkylation, isosurface, isocontours, gasoline, fractions, jet type, industry, oil refining

a method for calculation of electro-hydraulic raspylivatelja liquids. Theoretical dependences of the median diameter of aerosol drops on the fluid flow rate at different number of generator nozzle holes, on its main design parameters are presented.

Keywords: aerosol, dispersion, drop, generator, electrohydraulic atomizer

The article deals with the integration of a three-dimensional model of a parametric architecture object created by Autodesk Revit and its finite element model. The features of IFC formatting expand the possibilities of presenting design data for solving problems of integration information and computational models. The advantages and disadvantages of this approach to the modeling of unique high-rise buildings, the architectural solution of which is a complex geometric surface, are illustrated. The resulting finite element models allowed us to perform a static calculation and analyze the characteristic movements of the frame elements of a unique building. The practical significance of the presented research results lies in the possibility of using a parametric architecture for designing objects using BIM with subsequent analysis of the stress-strain state of the frame of a building or structure.

Keywords: information modeling, parametric architecture, finite element method, architectural model, calculation model, integration, IFC formatting

The article presents the results of an experimental study of methods and means of technical diagnostics of the engine cylinder-piston group during cold, idle scrolling of the crankshaft

Keywords: cylinder piston group, gas flow from the crankcase, technical conditions of the experiment

This article contains a survey of the building in the city of Rostov-on-don. A detailed visual inspection of the object of study, assessment of the technical condition of the main bearing building structures, analysis of the causes of defects and damage, pre - installation of the category of technical condition. As a result of the survey developed recommendations for the design, measures to restore or strengthen the building structures.

Keywords: technical condition, categories of technical condition, inspection, visual inspection, detailed examination, building structures, defect, damage, repair, restoration, operation

The legal status of water bodies implies special measures aimed at preserving and preventing negative processes within the boundaries of a water body. A zone with a special mode of use is the territory, within the boundaries of which the mode of using the object for the purpose of protection and (or) to protect the environment is established. In modern geodesy, special satellites are used that are part of the global positioning system. The object is tied to the existing geodetic network, the identification marks are laid in a minimal amount, then aerial photography is performed and the photoplans are “stitched”. The emergence of electronic and unmanned measuring instruments during a complex of geodetic works greatly facilitated the work of geodetic engineers, allowing them to increase the productivity and accuracy of work performed when using such instruments.

Keywords: water protection zone, zones with a special mode of use, water bodies, unmanned aerial vehicles, coastline, coastal protective strip, aerial photography, GNSS receivers, surveying equipment, orthophotomap