The article deals with the construction and definition of the stress-strain state of the design scheme of a lattice tower-like structure in the form of a mesh hyperbolic paraboloid. The dependence of the wind load distribution on the characteristics of the form is established, a sectional calculation method for such structures is given.

Keywords: Hyperbolic paraboloid, finite element method, aerodynamic loads, lattice towers

To ensure the stability of the galvanic deposition process and the high quality of the precipitate obtained, it is necessary to know the dependence of all processes on technological factors and modes. The degree of influence of technological factors on the behavior of machine parts made of gray iron, etching and deposition of zinc electroplating is not the same, so there is a need for electrochemical studies in the laboratory. The methodology of such studies has a General orientation and particular conditions in each case. The article describes in detail the method of electrochemical studies of gray cast iron in the sulfuric acid electrolyte of galvanizing during the restoration of machine parts by galvanic deposition of zinc coating. The basic conditions necessary for obtaining reliable comprehensive results that will determine the optimal conditions for galvanizing machine parts made of gray cast iron are considered.

Keywords: technological factor, electrochemical studies, polarization curves, electrochemical cell, electrode, potentiostat

The article discusses the dynamic characteristics of mineral wool materials (dynamic modulus of elasticity and stiffness, reduced dynamic stiffness) and the effect on them of porosity and relative deformation of the material. The main objective of the study is to determine the value of the dynamic modulus of elasticity, taking into account its change with time under the action of a long-term static load for calculating the impact noise insulation.

Keywords: mineral wool material, dynamic modulus of elasticity, strength of parts of a structure, sound insulation, ultimate states, construction

Within the framework of the two-fluid Landau theory, flows into helium II inside a rotating cylinder are investigated. Special attention is paid to the analysis of excitation by centrifugal forces of counter-current (by super-fluid and normal components) flows. In the approximation of incompressible fluid, an analytical solution of the equations of motion, vortex-free for both components is obtained. The tangential velocities for it are the same as those of a rotating solid body, with the normal and superfluid components moving in opposite directions, with different angular velocities. It's resulting vorticity is compensated by a spiraled counter-current radical movements. Such solution has no axial symmetry and has a tangential gap along the radius. Despite its instability, it is of some interest. First, it can be corrected by stabilizing deformations. In addition, it shows the paths of loss of stability of high-symmetric States. In particular, in our opinion, this type of disturbance are intermediate flow from Landau (superfluid component is at rest) one to the rotation of the Feynman type (in the superfluid part of a system of vortices).

Keywords: helium II, rotating cylinder, two-fluid theory, counter-current flows, centrifugal forces, vorticity compensation

The article deals with the main problems of obtaining experimental data on drying liquid dispersed products. The main difficulties of using a moisture meter to obtain kinetic curves of drying difficult-to-dry liquid materials are given. On the example of lignosulfonate drying curves of samples of liquid product in different conditions are obtained. Presented that the application of the proposed method of the experiment on the moisture meter does not lead to early completion of the operation of the analysis of the drying process.

Keywords: kinetics, moisture meter, drying, moisture, solvent, evaporation, lignosulfonates

The use of ultrathin sand as the main raw material in the production of concrete made by semi-dry molding is relevant for many regions of Russia due to the lack of sand with a high modulus of grain size and solid stone. The article presents the results of the analysis of the possible use of sands with a modulus of particle size Mcr = 0.8-1.4 in pressed small-sized concrete paving products for sidewalks. Replacing ordinary sand up to 80% with fine-grained does not reduce strength and performance properties. The transition to fine-grained and silty sands reduces the cost of production.

Keywords: concrete, semi-dry pressing, knitting, ultra-fine sand, hyper-plasticizer, strength

The article is a structured source of relevant types of building materials, which are used in the design of facades of high-rise buildings and structures. The technological features of each of them are considered and examples are given from the construction practice, in particular, the city of Rostov-on-Don.

Keywords: High building, facade, panorama of the city, construction material, architectural-planning solution, atmospheric exposure, ""mirror"" material, economical raw materials, ventilation, combined facade

Over the last years there is much concern about the quality of execution and selection of the actual documentation in the registration proceeding of the facilities construction turn-over package. There is no exact consolidated catalog of as-built documentation in the new normative and technical literature. Each executive document represents as an application to various sources of regulatory and technical literature. Therefore, the article presents a divided into chapters detailed catalog of as-built documentation for the oil and gas facility construction. An explanation is given for each chapter for which purpose it is formed and what function it has in the general package of as-built documentation. The main aspects of the as-built documentation execution are considered, a list of the documentation and some recommendations on the facility commissioning to the Client are given. Additionally, there is a suggested recommendation on the execution and filling of the package (folders) of the construction as-built documentation. This article recommends a common procedure for filling out and arrangement of the document flow of PTW package and as-built documentation of construction and installation works and the commissioning of the capital construction facilities. The article clearly describes the goals: - Improvement of the quality of as-built documentation execution; - Organization of the process of preparation, making up and verification of the package contents and quality of turnover documentation for construction and installation works; - Conducing the as-built documentation to a uniform style, which provides a high degree of the documents identification and control over the execution of the quality of preparation and completeness of the turnover documentation for works and construction projects; - Making-up of the objects reporting documentation; - Making-up of a document collection of the objects and work performed; - Establishing of universal explanation of the normative requirements by the all participants in the construction process. The focal point of this article is to provide recommendations on the execution of the turnover documentation for the facility construction, as well as improving the quality of as-built documentation execution. This article is action-oriented and is aimed to help young professional of the production and technical department of contracting companies, specialists of the Capital Projects Department, construction control and customer companies.

Keywords: acceptance documentation, construction and installation works, client, document control department, construction quality control, technical production department

The article is devoted to the analysis of the physical essence of the process of reducing air pollution for the woodworking shop of the enterprise serving the objects of urban construction, within the framework of the physical and energy approach. According to this approach, wood dust is considered from the position of the theory of dispersed systems, which changes its properties under the influence of external dispersed systems. The whole process is gradually illustrated by a physical model of the process of reducing air pollution, as well as a scheme of transformation of the dispersed system (dust aerosol) in the process of reducing air pollution.

Keywords: environmental safety in construction, the object of urban construction, dispersion system, woodworking shop, wood dust, air pollution reduction, physical and energy approach, physical model of the process of reducing air pollution.

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