Currently, more than 80% of water conveyance structures worked much the normative life. At the same time there is a simultaneous increase in the load on the aging waterworks, in the absence of the necessary skilled personnel and technical repair base will inevitably lead to an increase in the number of accidents due to operational reasons. Identification of factors that influence the condition of the facilities at the intersections , the search for methods of calculation and control of non-destructive methods to evaluate their work , life extension , etc. is of paramount importance at this stage. Residual life for the safe operation of water conveyance structures determined on the basis of system analysis with the development of the block diagram of a dynamic system having a number of subsystems. The main property that determines the life of the system , is the reliability of its elements , ie reliability and trouble-free operation for a certain period of operation. Dependability and reliability of the system as a whole is determined by the condition that each element of the system can be in one of two states - serviceable or failure.
Keywords: water-conducting structures, low head hydro closed spillways, modeling, technical condition, residual life.
The combination of the unique, abnormal properties shown by oxidic systems with structure of spinel on the basis of transitional elements chromites draws attention of researchers for many years. Some systems on the basis of transitional elements chromites (for example, nickel and copper chromites) have critical elements (multicritical points, lines of phase transitions of the second sort, etc.) on the phase chart. Near these elements of the phase chart materials possess unique chemical and physical properties. Therefore development methods of receiving and research of phase forming and properties in NIO-CoO-CuO-Cr2O3 system represent fundamental and practical interest for chemistry and technology of inorganic substances. In this work processes of spinel structure formation in system 0,6 NiCr2O4 – 0,2 CoCr2O4 – 0,2 CuCr2O4 from crystal chemistry positions are considered. Formation of two solid solutions on the basis of nickel (II) chromite – with structure of cubic spinel and with tetragonal distorted structure is established. The influence of cooperative Yahn-Teller effect on processes of a spinel forming and on stabilizing impact of chloride of potassium on process of education of two spinel solid solutions is suggested. Influence of a power factor of cation stabilization in knots of a crystal lattice as one of the important factor in reaction of spinel structure formation is considered.
Keywords: spinels, chromites of transitional elements, Jahn-Teller effect
The paper is devoted with the analysis of sources and volumes of oil components’ input into the Black sea. The topicality of this problem is connected with of transboundary the status of water object that contributes to the complexity of such works. Black Sea has important significance for transport and development in the coastal zone of the oil complex, combined with a great recreational potential. As a result, ecosystems are technogenic impact. The paper describes the main natural and anthropogenic sources of oil components in the Black Sea. On the basis of the results of our expeditionary research and analysis of sources of pollutant concluded chronic character oil pollution of the Black Sea. And the conclusion that the most optimistic estimates, entrance of oil components in the ecosystem in the Black Sea is approximately 270 thousand tons per year, which is higher than the currently accepted values of 2−2.5 times.
Keywords: sources, volumes, oil components, the Black Sea, hydrocarbons
Maximum power pointtracking algorithms are widely used in the solar converters in order to obtain maximum power from the solar array. The article provides a brief description of the work of these algorithms, description of the method of testing based on mathematical modeling using Matlab, Simulink and SimScape packages. The results of modeling and comparative analysis of the studied algorithms, its strengths and weaknesses revealed.
Keywords: maximum power point, maximum power point tracker, photovoltaic, buck converter, comparative study of algorithms, perturb and observe method, constant voltage method, constant current method, icremental conductance method
The methods of improving the efficiency of thermal power plants. Improve the efficiency improvement offers reach the combustion process. Outlines the benefits of controlling the combustion of fuel in the ion current signal.
Keywords: power system, power plants, combustion control, the ion current, the detonation
The modification of the most common steganography method for various container is presented. This modification allows to increase the resistance of steganography to the statistical analisys. A comparative analysis of the effect of the traditional LSB matching method and the proposed modification to the frequency histogram of sample values in the container is presented.
Keywords: steganography, steganalysis, information security, embedded data transfer
Fe-doped AlN nanorods were studied by means of x-ray absorption spectroscopy above the Fe K- and L2,3- edges. Theoretical simulations of the x-ray absorption spectra show that Fe atoms mainly substitute Al. A minor fraction of Fe interstitials or Fe-Al-N ternary alloy can be identified as well. Bader’s AIM analysis predicts that neutral substitutional FeAl defect is in 2+ charge state, though Al in pure AlN is in 3+ charge state. Fe L2,3 absorption spectra and photoluminescence data indicate the coexistence of Fe2+/Fe3+ in AlN:Fe nanorods so different charge states of substitutional FeAl should co-exist.
Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production
The advanced multispectral method is developed for formation and recovery of the image of a hypodermic on the basis of function of a detuning and its algorithm realizing. The method reduces distorting influence of change of characteristics of skin on image formation. Use of function of a detuning allows to make processing without observance of rigid requirements to the accuracy of a choice of lengths of waves on which images and, respectively, providing a preset value of the relation of values of optical thicknesses of skin are formed.
Keywords: Restore images, multispectral method, the function of detuning, the optical thickness, the reflection coefficient
This article reviews systems of respiratory activity registration in relation to sports medicine. Attention is devoted to the use of miniature accelerometers that record the movement of the chest, as the optimal method for the diagnosis of the respiratory parameters. Other methods are based on piezo-resistive sensors, pressure and airflow sensors, and airways resistance sensors. The authors' developed device based on three-axis accelerometer is proposed. It recognizes episodes of apnea with sufficient accuracy for long-term monitoring. The algorithm of the accelerometer data processing is described. In order to minimize noise impact on the useful signal it is necessary to transform the three-dimensional cloud of accelerometer data into a flat sector. Then the relation of gravity vector deviation angle and the nominal position in time is determined. This presented device due to its ability to transmit data via Bluetooth technology, after appropriate software development for mobile phone and the receiving terminal of medical professional, will be able to organize a simple ergonomic long-term remote monitoring of respiratory activity.
Keywords: systems of respiratory activity registration, long-term remote monitoring, three-axis accelerometer
In this paper we study of the local atomic and electronic structure of nanostructured condensed material for rechargeable current sources on the basis of 15mas.%V2O5/Fe/LiF nanocomposite within charge-discharge cycle. Principle component analysis (PCA) of the series of Fe K-edge spectra collected during 1 st charge showing the concentrations of the components Fe, FeF2 and V[FeV]O4. We found the changes in the V oxidation state from the analysis of the experimental Fe K- and V K- XANES spectra. Total and partial density of states of components are presented.
Keywords: nanostructured materials for rechargeable current sources, dynamics of local atomic and electronic structures, XANES, DFT
The catalytic activity of Pt/C and PtxNi/C electrocatalysts prepared by borohydride methode was studed. It was established that the specific activity of fresh prepared Pt3,7Ni/C catalyst in oxygen electroreduction reaction is higher in compare with Pt/C material. After treatment of Pt3,7Ni/C material in the hot acid nickel in the surface layers of nanoparticles was dissolved and the composition of nanoparticles was changed to Pt5,6Ni. The electrochemical surface area of the Pt5,6Ni catalyst and specific activity was slightly decreased after corrosion treatment.
Keywords: platinum electrocatalysts, corrosion stability of the nanoparticles, fuel cells, X-ray diffraction, borohydride synthesis
The problems of building the architecture and design of the database structure for the storage of the structure of the chemical compounds and their analysis using heuristic algorithms
Proposed the structure of the database that allows you to store information about the structure of chemical compounds with varying degrees of detail. This approach simplifies forming of the structural descriptors used to build models of "structure-property" based on the genetic algorithms.
Keywords: database architecture, chemicals, data mining, heuristics
Information base of textile textures and materials, with the detailed description of the software for work with base is considered. It is told about methods of creation of base of textile textures and materials and about opportunities of the represented project.
Keywords: informatsionnno base, textile industry, texture, materials, visualization, software, graphics
The article is concerned with designing online identification algorithm for identification plunger model for wicket gate of Kaplan turbine adaptive control system. Algorithm is based on generalised recurrent least square method and invariant embedding method. Computer modeling using designed algorithm and using real experimental data shows that algorithm is effective.
Keywords: adaptive control system, diagnostic system, Kaplan turbine wicket gate, plunger, linearized models, identification, recurrent least square
The mixed finite element method has advantages over classical formulations of Lagrange and Castigliano, and ensures high precision and smoothness approximate solutions for strains and stresses.
In practice, using the mixed finite element method is limited by high size of linear equation systems, which leads to significant increasing time costs.
Using the orthogonal finite functions for approximating of unknowns leads to generation of sparse linear systems with a special structure.
That system can be simplified during solution.
This article proposes the algorithm of modificated Gaussian elimination for preliminary transformation an extended matrix of linear system.
This algorithm underlies software complex, which includes LISTSOLVER, the author's solver.
Confirmed the efficiency of created solver in compare with common-type solver.
Keywords: mixed finite element method, sparse linear systems, orthogonal finite functions, Gaussian elimination