Ceramic materials based on solid solutions La2-xSrxMO4, where M is Ni, Fe, Co, Cu, x = 0, 2 with layered K2NiF4 structure (structure of Ruddlesden-Popper) have been synthesized and investigated. The correlation of dielectric properties with a normalized bond lengths of the metal-oxygen has been observed. The existence of nickel atoms in the 2+ oxidation state for nickelates has been shown.
Keywords: solid solutions, colossal dielectric constant, resistivity, x-ray diffraction, dielectric spectrum, XANES, low-resistivity semiconductors, the activation energy, the distortion of the coordination polyhedra, oxygen non-stoichiometry
The questions connected with an assessment of mechanical characteristics of steel elements of designs of tribunes of Torpedo stadium in Taganrog are considered. The analysis of the strength characteristics of metal of columns received by a nondestructive method, beams, the top and bottom belts of farms and раскосов is provided. Results of processing of values of mechanical characteristics on compliance most are shown to the general law of distribution of Veybull. For values of a limit of fluidity and strength scale and form parameters, and also shift which defines critical bottom possible value of the mechanical characteristic of theoretical distribution are received. The analysis of accessory of metal of the surveyed elements to the corresponding class of durability of construction steel with the conclusion that all metal of the surveyed elements has a class durabilities not lower than C 255 that meets requirements imposed by the project to durability of metal is given.
Keywords: nondestructive control, mechanical characteristics, durability, diagnostics, class of durability, metal test
The article considers the method of parameters selection of the stress testing parameters of the load testing system, which is used to evaluate the performance of a distributed monitoring system. The proposed method on the use of intelligent technologies, namely the fuzzy logic is based. The novelty of the proposed method in comparison with existing methods is use both fuzzy logic and feedback. Feedback allows getting information about the parameters of server performance of monitoring system and timely adjusting of parameters of the test system, providing the required load on server of monitoring system. A method of fuzzy logic allows responding flexibly to changing the state of the monitoring system, without human intervention, using the information obtained through feedback. To illustrate the proposed method was implemented in an experimental load testing system. Further experimental verification was performed of the implemented load testing system on a simple monitoring system. The final part of the article presents the results of the experiment. The experimental results show that the proposed method allows keeping the required load on the monitoring system server with various changes of states of its work.
Keywords: fuzzy logic, feedback, load testing, monitoring system
This article describes the issues on the basis of scientific research and the data produced in-depth analysis of technical condition of water spending long maintained facilities for further classification of defects and damages, as well as the prediction of their remaining life. Mathematical and software was built on the length of the projected water filtration since the beginning of the construction survey. Program - technical complex in the survey predicts the loss of bearing capacity as the structure as a whole and its constituent elements from the moment of injury. In the future, software and hardware predicted time total loss bearing capacity of the construction, using various regression dependence. Technical possibilities of application systems allow calculation of the geometric characteristics of different defects and damages on the surface of structures, and in some of its elements. Presented Program - technical complex for solving the problem of forecasting residual resource of water conveyance structures can be used to create a database during the operation of these structures over a long period of operation that will extend the life cycle of water conveyance structures with regard to their reliability parameters. The basic provisions on the organization of determination and prediction of residual life long maintained water conveyance structures, identification of defects and damages, assessment of suitability taking into account the reliability of the parameters, for further use water conveyance facilities.
Keywords: monitoring, automation, carrying water facilities, livneotvodyaschie facilities, software and hardware, reinforced concrete, technical condition.
We investigated the creep of concrete arches based on the following theories: the theory of linear creep by Harutyunyan-Maslov, kinetic theory, the theory of flow, theory of aging, and nonlinear theory of Y. Gurieva. We considered viscoelastic model of the concrete, ie total strain was represented as the sum of elastic strain and creep strain. Solution of the problem was carried out by finite element method. We considered the arch rigidly clamped at the ends and loaded with a uniformly distributed load. Graphs of growth of deflection and stress distribution in the reinforcement and concrete are represented. We obtained the substantial redistribution of stress between the reinforcement and the concrete during creep: in reinforcement stresses increased and in concrete stresses decreased. The strongest redistribution occurs on the theory Y. Gureva.
Keywords: reinforced concrete arch, creep theory of heredity, aging theory, the theory of flow, kinetic theory, finite element method, stress-strain state
Failure of communication equipment and automated control systems by the fire of the State Fire Service of the Ministry of Internal Affairs of the Russian Federation, leads to a significant reduction in staffing it and, as a consequence of this, to the disruption of assigned tasks. Proposed generalized analysis allows to take into account all the factors affecting the recovery process as a single sample and the communication system and create a conceptual model of the recovery process communication equipment repair bodies of technical communications and automated control systems of the State Fire Service of the Ministry of Internal Affairs of the Russian Federation.
Keywords: communication, communication technology and management information systems, technical support communication and control systems, recovery, repair, maintainability.
The article describes the slow flying drones with reference to problems of aerial photography. As an alternative to multicopter proposed aerodynamic design, elliptical flying wing. It has been shown that this scheme allows ensure uniform distribution of lifting force along the wing span, respectively, does not allow on loss of unmanned speed bogged down into a tailspin. The results of mathematical modeling and flight test a prototype of this type of UAV.
Keywords: unmanned aerial vehicle; elliptical wing; control laws; mathematic modeling; drone aircraft
This article discusses the concept of information security, its structure and development stages, shows the diversity and the equivalence of the remedies and discusses existing approaches to the formation of protecting corporate systems on the basis of which it was proposed to address this problem, based on the method of decision theory.
Keywords: information security, information security devices, knapsack problem, points of placement of remedies of information security, the formation of information security, distributed systems, mathematical model
The article discusses the generalized algorithm of processing of weakly formalized information in technical systems on the example of the control of non-equilibrium chemical reaction such as the Belousov-Zhabotinsky reaction. The reaction occurs in a container placed in a thermostat. By container summed tubes on which the container through the valve receives a reagent solution. The contents of the container is stirred with a mixer. In the container occurs reactions, and the excess solution is drained through the drain. The problem is following. It is necessary valves that regulate the rate of arrival of solutions into the container and stirrer speed adjusted so as to obtain a stable periodic repeating pattern. In the reaction can be seen as a change of color of the solution from red (high concentration of cerium ions with a valence of 3) to blue (high concentration of cerium ions having a valence of 4) and back to the period of a few minutes. In the article described in detail the use of the generalized algorithm to solve of the problem of regulating of valves and mixers in the container.
Keywords: weakly formalized information, information processing, algorithm, non-equilibrium chemical reaction, Belousov-Zhabotinsky reaction, control
Failure of communication equipment and automated control systems by the fire GPS MES of Russia, leads to a significant reduction in staffing it and, in consequence, to the disruption of assigned tasks. The proposed conceptual model and its verbal description allowed to identify bottlenecks in the process of restoring the vehicle to repair the organ, and in its financial support in the form of appropriate repair kits of spare parts, as well as its efficiency in the reduction of the distribution group damaged samples according to multiplicity created ZIP.
Keywords: communication, communication technology and automated control systems, technical support communication and automated control systems, recovery, repair, maintainability..
The system is intended to automate the procedure of 3D-models calculation and formation for cooling heatsink of electronic components. Based on user input, the system calculates the design parameters of the heatsink in the mathematical core, then data enters the geometric kernel, where the construction and rendering of 3D-model takes place. The system allows to choose the type of heatsink being constructed, the method by calculations will occur, dimensions and material properties. The result is a 3D-model of the heatsink suitable for use in the design process.
Keywords: heatsink, computer-aided design, automation system, radioelectronic equipment, parameterization, geometric modeling, API
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
Computer-aided design (CAD) and computer-aided manufactoring (CAM) have became an increasingly popular part of dentistry over past 25 years. The technology, which is used in both the dental laboratory and the dental office, can be applied to inlays, onlays, veneers, crowns, fixed partial dentures, implant abatments, and even full-mouth reconstruction. This article discusses the history of CAD/CAM in dentistry and gives an overview of how it works. It also provides information on the adventages and disadventages, describes the main product available and addresses future applications.
Keywords: Computer-aided design, computer-aided manufactoring, dentistry, user-computer interface
Technology mechanical point-shock engraving on photo printer for printing on products is particularly popular among specialists designers because the entire process of creating images and computer training to the engraving is very creative and at the same time allows you to make adjustments to the customer at any stage without much effort or loss of quality and time. To solve this problem it is necessary to analyze the causes of the marriage; determine the types of marriage by using technology of printing on the surface of the product mechanical point-impact photo printer and suggest methods to eliminate it.
Keywords: marriage, photo printer, dot-impact engraving, image distortion parameters blanks
The article presents basic equations for reinforced concrete elements that are experiencing bending moment and axial force, taking into account the creep of concrete. The stress-strain state of reinforced concrete statically determinate three–hinged arch is investigated on the basis of these equations. Also for this task we gained the resolving equations of finite element method and compared the numerical-analytical calculation with the numerical performed using the finite element method to the arch loaded with a uniformly distributed load and having the shape of a circular arc. The calculations used viscoelastic model, according to which the total deformation is the sum of concrete elastic deformation and creep. We consider a rectangular cross section with symmetrical reinforcement. It is shown that because of creep stress redistribution between concrete and reinforcement arises.
Keywords: finite element method, the creep of concrete, viscoelasticity, reinforced concrete arch, the stress–strain state.