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  • Calculation of the strength of reinforced beams with an aggregate of bimodulus of elasticity material with the use of different theories of strength

    The paper considers arbitrarily supported arbitrarily loaded reinforced, beam with an aggregate of bimodulus of elasticity material. Formulas for determination of the tangential stresses arising in the aggregate, subject to the reinforced elements. Formulas are obtained for principal stresses occurring at an arbitrary point in the aggregate, as well as the equation for determining the point where major stresses reach extreme values. Are terms of strength as the classical theories of strength, and strength criteria applied for calculation of constructions made of bimodulus of elasticity material.

    Keywords: reinforced beam, bielastic modulus, stress, normal concrete, strength criteria.

  • Automatic device for analysis the nonlinear parameters of HTSC ceramics YBa2Cu3O7-x in variable magnetic fields.

    Considered part of the software and hardware designed and manufactured the device for the automatic analysis of nonlinear parameters of high-temperature superconducting ceramics YBa2Cu3O7-x in variable magnetic fields. Shows the calibration and specifications. The new is a synchronous (the error in determining the phase of no more than 0.5%) of digital signal samples of the nonlinear response of the sample and the samples generated by an external magnetic field (the error is less than 1%), with the number of data samples per channel to 90 ∙ 106 12-bit samples and sampling 600 ∙ 103 samples per second. The reference range of variable magnetic fields 1 - 50 Oe, a frequency range of 1 - 50 kHz in steps of 1 Hz and the accuracy of 0.0291 Hz. The device has an interface to the computer via two USB-interface and original software to work with it. With the use of the device, a series of experiments designed to produce some non-linear parameters of cylindrical sample made of high-Tc ceramic YBa2Cu3O7-x. The analysis of the results and their comparison with the presented in the literature  

    Keywords: Nonlinear medium, high-temperature superconducting ceramics, synchronous samples, harmonics, ARM-9 CPU, a differential sensor.

  • The synthesis of the concept of the upgraded version of the adaptive friction clutch with a combined feedback

    In a modified version of the adaptive clutch size of the spacer strength decreases due to a reduction of torque, which transmits the additional friction group, including, for the maximum value of the friction coefficient. Therefore, to save the value of the brace force is necessary to increase the ratio usileniya.Predlozhena concept modernized version adaptvnoy clutch with a combined feedback based on the formalization of the distribution of power factors for the closure of the main steam friction of the friction and more friction groups, allows you to simplify the design of the coupling compared to the base case  

    Keywords: the coefficient gain, a separate positive connection, the coefficient of friction, clutch, friction pair

  • The experience of building piled foundations of the piles on nonuniform basis during the construction of a 17-storey residential building in Rostov-on-don

    The article describes the experience of the device of pile foundations under the multi-storey building in difficult engineering-geological conditions in Rostov-on-don

    Keywords: Drilling piles, test, conductor pipe, sandconcrete, foundation

  • Processing and filtering signals. State of the art

    An overview of research related to the tasks of processing and filtering of signals. Signal is considered as a random process defined by probabilistic characteristics. This article addresses the issues of the history of the development of methods of signal filtering. Recent scientific publications in which the results and the main directions of research in the field of signal processing and filtering are analyzed. Presented material extends the current state of knowledge about the problem.

    Keywords: signal, signal filtering, signal processing, stochastic process

  • Methods for the synthesis of LaMnO3 (Review)

    "This review covers various methods of synthesis LaMnO3 ferroics. The general analysis of the solid-phase synthesis reactions methods and wet methods (sol-gel, sorption, co-precipitation) are carred out. The original results of LaMnO3 syntheses from various precursors by means of the in situ method are showned. The advantages and disadvantages of different methods of synthesis are determined. The analysis of synthesis LaMnO3 ferroics published data is shown:
    - the structure formation of LaMnO3 in perovskite-type phases occurs at different temperatures, depending on precursors states;
    - LaMnO3 perovskite phases differ in symmetry and unit cells parameters at room temperature, depending on the preparation conditions;
    - the highest synthesis temperature of LaMnO3 are typical for solid phase reactions method (950-1050 ° C), the lowest - for wet synthesis methods (500-700 ° C);
     - the synthesis conditions effect the stoichiometry of LaMnO3 for oxygen content.
    Our studies of structure formation processes of LaMnO3 by in situ method are allowed to define the role of precursors states at synthesis of solid phase reactions methods, adsorption, co-precipitation and sol-gel mixtures.
    It is determined that in samples prepared by wet chemical methods, the formation processes of  LaMnO3 perovskite phases occur at lower temperatures than by solid phase reaction (sol-gel precursor - 500 <T <600 ° C; precursors obtained by coprecipitation and sorption methods - at 600 <T <700 ° C and 700 <T <800 ° C, respectively).  

    Keywords: ferroics, LaMnO3, X-ray diffraction, solid-phase synthesis, sol-gel synthesis, sorption, co-precipitation

  • Thermostability of oxide alkali tungsten and molybdenum bronzes

    Oxide bronzes MxEO3 (M–Na,K; E – W,Mo) are the inorganic materials for technics and chemical technology. Its properties, for example stability in wide interval of temperatures, are of great practical interest (electrodes for fuel elements, electronic apparatuses  and others).                                                                             In this article the results of studies of thermostability of sodium and potassium tungsten and molybdenum bronzes in atmosphere and vacuum condition at the temperatures range 20-1110°C were found. The samples are prepared by electrolysis of melts of sodium and potassium isopolytungstates and molybdates. Dates for bronzes Na0.92WO3 , Na0.68WO3 , Na0.53WO3 , Na0.15MoO3, K0.3MoO3 were characterized by the termogravimetric-differential- thermal analysis (TG-DTA). Regions of stability of Na0.92WO3 : 20-700°C , of MxMoO3 : 300-500°C were founded. Conclusion about correlation of  nonstoichiometry of chemical composition of EOx bronzes and oxides, which making important role in formation of less - common metal bronzes structure.

    Keywords: oxide alkali bronzes, tungsten, molybdenum, thermostability, nonstoichiometry, thermal analysis

  • Laser interferential thermometric measurement of high frequency (HF) and super-high frequency (SHF) energy density

    There submitted a HF and SHF field energy density measuring technique developed by authors in this work with application of semiconducting laser interferometer measuring an alteration of a glass plate optical thickness while the plate is placed in the sphere of HF or SHF heating. Operability of the technique is demonstrated by measurement of a microwave oven electromagnetic field energy density distribution

    Keywords: laser interferometer, temperature measurement, HF and SHF field sensor

  • The calculation of the optimal value of the protective layer of concrete columns of square section

    An approach to the calculation of the optimal values ​​of the protective layer of longitudinally reinforced concrete columns, operating at a central compression. Modeling performed using FEM - Ansys package for the design and implementation of spatial models of flat section of the column.

    Keywords: reinforced concrete column, longitudinal reinforcement, a protective layer of concrete, finite element method, critical load

  • The extent of the stress-strain diagram of eccentrically compressed concrete pillars

    On the basis of experimental data on the resistance of reinforced concrete columns eccentric compression was obtained analytical dependence of the limiting compressibility of concrete from the varied factors: the relative eccentricity of the external force eo / h and the reinforcement ratio μ.

    Keywords: reinforced concrete column, longitudinal reinforcement, a protective layer of concrete, finite element method, critical load

  • Research of the influence of the development level of intelligent transport network on the efficiency of intermittent bus lane priority application

    The article deals with the analysis of intermittent lanes priority based on simulation. The implementation of intermittent lanes priority system is only possible within the framework of urban intelligent transportation system (ITS).  In some cases, there are not always enough ITS components for the operation of intermittent lanes priority system. Based on the simulation it is possible to determine the efficiency of the intermittent lanes priority system with the minimum or complete number ITS components. To compare the effectiveness of intermittent lanes priority system the simulation was performed for the four scenarios:
    1. Without the use of public transport priority
    2.  Classically  marked priority lane
    3. Using the intermittent lanes priority system with a minimum number of ITS components
    4. Using the intermittent lanes priority system with the full amount of ITS components 
    According the results of simulation we concluded that the minimal intermittent lanes priority system is noticeably inferior to a fully functional intermittent lanes priority system on the effectiveness, but such system does not require a high level of development of the urban ITS and can be considered as the first stage of a complete intermittent lanes priority system.  

    Keywords: the organization of the bus lane priority, priority lane, intermittent bus lane priority, road capacity, controlled road signs, intelligent transportation system

  • The choice of boundary conditions for the simulation of the temperature field of soil

    The existing methods of calculation of the annual change in soil temperature. Identified areas of their application and the possible deviations from reality. The requirements to the boundary conditions of the calculation. Defines the principles of the choice of initial conditions. The preconditions for the development of a universal method of calculation.

    Keywords: heat pump, renewable energy, solar radiation, transient mode, soil

  • Research of the influence of the development level of intelligent transport network on the efficiency of intermittent bus lane priority application

    The article discusses an innovative organizing method of the buses priority - a intermittent bus lane priority.

    Keywords: the organization of the bus lane priority, priority lane, intermittent bus lane priority, intelligent transportation system

  • Modeling technology changeover

    The paper examines the main approaches to the modeling of scientific and technical progress. Details the conditions and change the model postulates technological structure , its main provisions . Put tasks that are of great interest for scientists involved in the modeling of scientific and technological progress , and for economists who are interested in the practical application of these results . Values ​​of other well-known models of STP . The variants of modernization and the possible synthesis of these approaches to modeling change tehnologichekogo order.

    Keywords: scientific and technological progress, advanced technology, changing technological way of practical experience, the elasticity of factor capital

  • Information content of the frequency characteristics of N-gram of the websites text fragments for search systems

      The work in the Internet is impossible without the use of search systems. The quality of the responses to user’s requests to a large extent depends on the keywords. However, due to some circumstances the user is not able to accurately enough to formulate a request and the number of received responses is great. In these situations, additional feature relevant answers selection can be text documents belonging to a particular implicit group. Implicitness group is shown in the fact that the text belongs to it is determined not by direct comparison with the reference (key) words, but by matching the semantic features, the wording of which is absent in the search text. Implementation of text classification can be made on the basis of the frequency characteristics of N-grams. The purpose of the work is to assess the possibility of using the frequency characteristics of N-gram of the websites text fragments to improve search engine based on a study of their information content. In this work designed a method based on the selection of informative indicators of N-gram with low computational requirements and with application of the correlation analysis. Based on its application has been shown that the frequency characteristics of N-grams have sufficient information content to improve search engines. The developed method has many common with systems of writing, because it relies not only on the alphabetic systems.  

    Keywords: N-gram, request, semantic features, search engine