"This article provides a solution of the plane contact problem with the use of a finite-element method. It presents the algorithms to determine the “node – response surface” contacting pairs through method of minimal penetration of contacting bodies. The article also contains the algorithm of rapid formation of the global stiffness matrix, taking into account the changes of the connections between mesh nodes for each iteration of solving in the Mathcad software."

Keywords: solution of the contact problem, flat stress strain state of the finite element method, Mathcad

With the safety position and the environmental and economic feasibility of perspectivity renunciation of the use of imported liquefied chlorine (substance of 2 hazard class) and replacing it with an electrolytic solution of sodium hypochlorite (4 hazard class), produced by on-site consumption. Hydrogen, which is a waste product , is thus partially (15-20%) to reduce the need Rostov TEP-2 in this matter and to provide a corresponding reduction in energy and economic costs.

Keywords: liquefied chlorine, sodium hypochlorite, hydrogen, emergency, chlorination plant, hydrogen generation, energy efficiency, resource conservation, safety

The article analyzes the calculation of the punching shear slab structures according to the recommendations of SNiP 2.03.01-84*concrete and reinforced Concrete structures. It is shown that the existing method of calculation gives overestimated the bearing capacity of floor slabs in bezrigelny frame systems. In order to establish the bearing capacity corresponding to the constructive decision is expected by calculation to determine the angle of the pyramid pushing.

Keywords: extrusion, dowel effect, bezrigelny frame, preopera area, bearing capacity, punching the pyramid, technological hole, slab, reliability, rebar, concrete

The article contais numerical analytical solution of the contact problem with termal creep of main material, based on the limited precision of machine arithmetic and practical significance of the result. A solution of the 2nd kind Volterra integral equation , which is the main task of resolving equations is made by replacing the integrand function and the introduction of "conditional indefinitely". The article contais analysis of the behavior of the function with all changes.

Keywords: "solution of the plane contact problem numerical solution material termal creep"

"The article treats the issues of data exchange between Mathcad and Gmsh. To solve this problem built-in and predefined functions are used in Mathcad without recourse to UFI tools. The solution proposed in the article is connected with importing a mesh with a complex topology into Mathcad for further processing with the use of numerical methods. The solution involving a partially automated transmission of the results of calculations in the nodes of spatial mesh cells for further visualization is also considered in the article."

Keywords: visualization of numerical results, transfer mesh with complex topology, Gmesh, Mathcad

In the various methods of non-destructive testing, which working with the deformation fields, diagnostic accuracy is largely dependent on the intensity of structural noise caused by small-scale irregularities of building structures. In this paper we investigate the effectiveness of using a vector-scalar receiving systems for diagnostics of vibration and defectoscopy of building structures. Comparative analysis of the fluctuations of the scalar and energy flux components of the structural noise acoustic field was conducted using computer simulation. Suppression of this noise contributes to a more precise localization of defects in constructions. The study was conducted in view of the fact that the component of the stream of the acoustic field, for which the intensity of the structural noise is minimal, is measured indirectly, using two sensors: scalar and vector. It is shown that the use of energy flux component can increase the detection efficiency.

Keywords: flaw detection, structural noise, fluctuation, components of the acoustic field, energy flux

The maintenance model of group of stationary objects in a one-dimensional working area by moving processor is considered. The processor performs one-step service cycle without interruptions, which begins and ends at the base point. For every object assumed to be given its location, the required length of service, an early start of service and function of the individual fines. We study the problem of multiple criteria, where total traveled processor length, time of return of the processor in the base point after the service of all objects of a given group and the total fine value of all objects act as minimized criteria. The solution is performed using formulas based on the principle of dynamic programming, and also based on the ideology of evolutionary genetic algorithms. When using dynamic programming we study questions of construction of complete sets of effective assessments. The problems of comparing two sets of estimates, the computational complexity, an example and results of the experiments are considered.

Keywords: multi-objective optimization, maintenance strategy, dynamic programming, evolutionary computation, NP-difficulty, mobile processor, stationary objects

In this paper we propose mathematical model of implicit-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 nonsalient-pole 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 implicit-pole synchronous generators.

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

Calculate the aerial and / or hydrodynamic effects from the continuous medium required for the synthesis of an adequate control system. Numerical simulation of movement managed position-control trajectory mini-ship at small angles of heel and the presence of sea waves on the basis of a fully-mathematical model and the proposed methodology for assessing the hydrodynamic impact.

Keywords: surface mini-boat, position-control trajectory, aerohydrodynamics, mathematical model, nonlinear dynamics, CFD modeling, external disturbances

The paper presents a new constructive solutions of concrete ribbed slabs with prestressed reinforcement coating , in which the edges stretched zones have stepped shape. This helps outline the cliff high prestressed reinforcement along the length of the element that allows you to increase the utilization rate of reinforcement in comparison with a standard solution.

Keywords: ribbed slabs covering equal resistance of prestressed reinforcement , stepped shape

The assessment of economy of the electric power and reduction of emission of greenhouse gases across the Nizhny Novgorod Region due to introduction of the equipment having marking in household sector, the budgetary sector and on other objects of energy consumption (buildings) on prospect till 2030 is carried out

Keywords: marking of power efficiency, engineering equipment, electrical household appliances

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 values the frequencies of the stretching vibrations of nitrit-, nitrat- and perclorat- anions in molten salts of alkali metals and their point group symmetry. There is a correlation with an increase in the frequency of symmetry.

Keywords: frequency Raman spectra, Raman spectra, melts, nitrites, nitrates, perchlorates of alkali metals, binary salt system frequency Raman spectra, Raman spectra, melts, nitrites, nitrates, perchlorates of alkali metals, binary salt system

The experimental temperature dependences of the basic MOSFET parameters (the transconductance parameter and threshold voltage) in a wide temperature range covering both cryogenic temperature and regular temperatures are considered. The methods which acceptable for engineering practice and allow to approximate the experimental temperature dependences of the basic MOSFET parameters by the simple analytical expressions in the form of linear or power functions are presented. The investigated MOSFETs was designed for work as active elements of amplifying devices. Temperature dependences of the basic MOSFET parameters are needed for estimation of the sensitivity, prediction of uptime and optimizing the choice of refrigerant for low-noise amplifiers.

Keywords: MOSFET, transconductance parameter, threshold voltage, temperature dependencies, approximation, cryogenic temperatures

The article provides an overview of the most common types of control valves used for process control in various industries. To accomplish the overall functions and control features in industry the control valves with an S-shaped body structure are used. However, to reduce the flow resistance and the acoustic pressure generated axisymmetric control valves can be used. регулирование, технологический процесс, конструкция, клапан, арматура, классификация, корпус, запорный орган

Keywords: control, workflow, design, valve, classification, body, valve plug