in modern conditions become widespread trenchless methods for the construction of pipelines. The positive features of their use include increased speed pipeline installation, reducing the volume of excavation, etc. Existing regulatory documents limit the bending of the pipe at low temperatures need to be tested in terms of their applicability to new grades of polyethylene. The aim of this study was to determine the minimum permissible bending radius of the track, the passage of which in the conditions of negative temperatures polyethylene pipes PE80 would maintain its strength characteristics. By using a mathematical model dependency of the elastic modulus and yield point are calculated from the temperature stresses in the walls of pipes of different diameters in bending under different temperatures. In order to establish empirical relationships voltage on the pipe diameter and the radius of its bend procedure is carried out function approximation method of least squares. Presented obtained graphic dependences. Using the values ​​of the yield strength of the material at different temperatures were calculated bending radius of all dimensions. If the production of the track plow trenchless pipe-layer will be considered given the conditions, you will be provided with the necessary conditions for installation.

Keywords: plastic pipe, trenchless pipe layer, the stress-strain state, trenchless techniques, pipelining

The article describes and analyzes how to determine the thermal residual stresses. The conclusion, based on the analysis, showed the necessity of the calculation method for determining the residual stresses, which is based on a mathematical model of the formation of residual stresses and deformations occurring during heat treatment. The results of calculation of stresses and comparison with experimental data are given.

Keywords: residual thermal stresses, finite element method, heat treatment, low-hard details

The phenomenon of buckling under the creep of concrete arches was investigated. Solution of the problem carried out by means of the finite element method. To analyze the stability we used Newton-Raphson method. It has been established that there is a long-term critical load, beyond which the growth of the deflection has not fading character. As the equation of the relationship between the creep deformation and strains we used viscoelastoplastic hereditary model of aging concrete. To determine the creep strain we used a linear approximation with respect to time. It was found that the long critical load for considered arch was in 1.44 times lower than the instant critical load.

Keywords: reinforced concrete arch, stability, creep, geometric nonlinearity, finite element method, Newton-Raphson method

In this paper we propose mathematical model of salient-pole synchronous generator of mini-CHP. The model is based on a full Park-Gorev differential equation. The saturation of the machine is taken by using the method of partial magnetic characteristics. This method allows most accurate evaluation of the change of parameters of an equivalent circuit of the generator in the absence of information about the magnetic properties of the machine. The model is Implemented in Simulink. Application of the model is possible when calculating the steady-state and transients in distribution electrical net wich contains salient pole synchronous generators.

Keywords: salient-pole synchronous generator, mathematical model, Park-Gorev differential equation, magnetic characteristics, transients

The article highlights main problems of agricultural development of KBR and basic measures of their solution. The necessity of state support of agriculture as a natural condition for the functioning of this industry is also justified.

Keywords: agriculture, government support, endogenous and exogenous factors, innovation development, technology

Infringements of variability of an intimate rhythm in a combination to attributes of electric instability of a myocardium are one of factors of diabetic heart.

Keywords: arterial hypertensia, diabetic heart, variability of an intimate rhythm.

The results received at research of influence electron beam treatment processings on tool life of a tungstenless hard alloy metal on the basis of TiC with a binding material an alloy Ni-Cr-Al and percentage of the components "basis-binding" 50 – 50% about are presented in the conditions of metal cutting. Influence electron beam treatment of a blanket of samples of the cutting tool insert on technological components of force of cutting when turning cut metal is experimentally revealed.

Keywords: Surface coating, hard alloy metal, structural and phase modification, electron beam treatment, tool life, metal cutting, wear, technological components cutting force

An analysis of science researches and production experience have shown that there is a need in the method of determining the number of vehicles and special technics for transport units in the pipeline industry. Decided to consider the system of transport and technological service of pipeline's repair processes as queuing system. A simulation method as a tool for determining the need of vehicles was chosen. The correlation between factors of primary production and the number of vehicles and special technics was determined.

Keywords: oil pipeline, car, special equipment, vehicle, demand for vehicles, modeling, quantity of technics, standardization, technical maintenance of cars

Problems for the design of low-voltage CMOS op-amps are considered: low voltage headroom for signal swings, increase the swing of input and output common-mode signal and sustainability when the feedback. Ways to implement input and output stages of low-voltage CMOS op-amps for technology 0.13 um at 1 V are investigated. The ways of frequency compensation are investigated. According to the results of modeling the best gain and the largest swing of input and output signal have continuous in time common-mode feedback circuit (CMFB) and the proposed two-stage current mirrors op-amp. These op-amps can be applied at a supply voltage ~ 1 V.

Keywords: low-voltage CMOS operational amplifiers (op-amps), the input and output swing, miller-effect frequency compensation

Developed a rapid method for evaluation of the homogeneity of mixtures hardly separated granular materials, the analysis of which is the use of known methods is impossible or time-consuming. The method is based on the separation of mixture components by color using computer processing of pictures of her samples. To implement the developed computer program that can calculate the values of the coefficient of heterogeneity of the mixture, as well as other dispersion parameters.

Keywords: express method, the concentration of the mixture, component, granular material, image, distribution, shade of gray, the coefficient of heterogeneity

The peculiarities of formation of mechanical properties of composite superconducting tyre during its rolling. To determine the intensity of the tangential shear stresses, intensity of deformation and microhardness for all components of the tire of the proposed method of research. The results can be used to determine the power parameters of rolling and determine the conditions of rolling without breaking.

Keywords: The intensity of the tangential shear stresses, the intensity of deformation microhardness

The paper presents the results of a study on the influence of seasonal conditions on the reliability of diesel and gas diesel vehicles. During the experiment were treated with statistical data on the failure of the two groups of trucks, methane-diesel and diesel operated under the same conditions. As a result of analysis found seasonal variations in the flow of failures between the two groups. Then the failures were divided into failures of components and assemblies cars such as engine, transmission gear and chassis of cars. This division has revealed the influence of seasonal conditions on the reliability of components and assemblies of diesel and gas diesel cars and their differences. Studies have shown the need for adjustment of norm in the planning of maintenance and procurement of spare parts for gas diesel vehicles.

Keywords: Stream failure, gas equipment, seasonal conditions, the reliability of vehicles, maintenance and repair

Modeling of parallel operation of distribution transformers with thyristor voltage and powe regulator are considered here. Models are made in Simulink. Structural model of parallel operation of two three-phase transformers is presented. Model allows us to study electromagnetic processes at phase by phase control.

Keywords: three-phase transformer, parallel operation of transformer, simulation, Simulink.

There was a need for geotechnical monitoring during construction of underground facilities. The organization of monitoring control tensile forces in the concrete anchors. Comparison of experimental and calculated data, which revealed that the deviation does not exceed 19%. When using anchor embedment length limited in a large range of conditions in a rod anchor having critical internal forces. To increase the efficiency of anchors in their construction can be used in flexible elements of the anchor bolt assembly.

Keywords: underground construction, monitoring, anchor well, tensile forces, the bearing capacity, the compliance node

The article presents the main results of theoretical and experimental research in the field of non-destructive testing and forecasting of geomechanical condition of the arched part of the transport tunnels. It has been shown that this goal can be to apply a method of acoustic resonance inspection. Methodology Research was registering the resonant response of the layered rock mass to impact mechanical excitation of an acoustic signal. Initiation and receive elastic vibrations produced in the lower layer of the breed. These technical and economic parameters allow to recommend Geophysical prediction described underground geophysical methods for wide industrial use during transport tunnels

Keywords: geomechanical state geological environment, the array, evaluation, arched part, the transport tunnel spectrum, acoustic resonance inspection, prognostication, control, forecast, weakened mechanical contact