×

You are using an outdated browser Internet Explorer. It does not support some functions of the site.

Recommend that you install one of the following browsers: Firefox, Opera or Chrome.

Contacts:

+7 961 270-60-01
ivdon3@bk.ru

  • Local Atomic Structure and Computer Modeling of the Copper Ion in Amyloid Beta Peptide: XAS Study

    Alzheimer's disease is an incurable illness. It affects about half a million people in Russia, and due to the general trend towards aging of the population the number of Alzheimer's disease cases will steadily increase. Insoluble deposits of amyloid beta in the brain tissue (amyloid plaques) are the major morphological characteristic of Alzheimer's disease. It has been found that the increased concentration of copper in amyloid plaques results in copper ions bound to the protein. It is the presence of copper in the binding site triggers of the formation of amyloid plaques. Therefore, the study of the binding site in amyloid beta is of great scientific interest. The local atomic structure of the Cu(I) copper ion binding site in the amyloid beta peptide has been studied by means of XANES spectroscopy. Several model structures obtained by molecular mechanics and density functional theory (ADF code) have been tested. Theoretical analysis of X-ray absorption spectra based on the finite difference method implemented in FDMNES code was performed. An appropriate model structure of the Cu(I) copper ion binding site in amyloid beta peptide has been found.

    Keywords: amyloid beta, binding site, Alzheimer's disease, the method of finite differences, Cu(I)

  • Change of the mechanism of sintering powders piezomaterials as a way of reducing the temperature of formation of dense ceramic frameworks

    The problem of manufacturing technology heterostructures pezofaza - metal considered in the article. Complexity consists in the fact that during the removal of the polymer in the system at low temperatures are formed porous layers, formed powders separated metal layers, having island macrostructure. One way to solve the problem - reducing the firing temperature heterostructures. Proposed to decrease the sintering temperature by using of functionally active glass-phases. Reducing the sintering temperature of products also allows to replace platinum electrodes inexpensive silver-based alloys. Obtained by solid state reaction method of piezoceramic material has a low sintering temperature (980 ° C) and high electrical parameters. Found that not only the proportion of the vitreous mass, but also their qualitative influence on the properties of piezomaterials    

    Keywords: heterostructure glass phase, the sintering temperature, porosity, ferroelectric phase

  • Change EFP materials PZT system by combining

    Piezoelectric ceramics on the basis of the phase of (1-x) PbTiO3-xPbZrO3 is the basis of most high-performance piezoelectric materials. Electrophysical and mechanical properties of these materials can vary widely in different ways. Traditional methods include changes in composition within the morphotropic region and doping. Now is the study of the influence of topical makrolegirovaniya the material properties of the PZT system. As a model system was selected phase of the PZT system, the compositions of which MO belong, one of which contains a dopant in the sublattice (A) and another - in the sublattice dopants (B). The studies established that one of the effective ways of varying the parameters piezomaterials may be the formation of solid solutions on the basis of two or more piezoelectric phases having different combinations of electrical parameters  

    Keywords: Piezoelectric ceramics, doping, kombinorovanie, pezofaza, piezo

  • Dynamic model of students' professional specialization

    A differential game theoretic model of the social partnership relations in the system of higher professional education is proposed. The state vector describes a level of students' professional level. Some approaches to the model identification and investigation based on simulation modeling and differential cooperative game theory are considered.

    Keywords: social partnership, higher professional education, differential cooperative games, simulation modeling, identification

  • Hybrid reverberation algorithm

    A hybrid reverberation algorithm is offered in this article. This algorithm is using both a convolution section in which a convolution with an inmpulse response of a real acoustic room is being implied and a mathematical reverb model. Also an algorithm for generating impulse responses of optional rooms is also offered in the following article. The algorithm efficiency calculation is  specified in the article. Thia reverberation algorithm is a part of a bigger complez auralization algorithm where it is being used coherently with an HRTF-based algorithm in order to simulate a real acoustic environment  

    Keywords: artificial reverb, room simulation, convolution algorithm, impulse response convolution, impulse response synthesis, dynamic convolution, complex filtering

  • 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.

  • Model of application of system mimo for suppression of reflections from the surface of earth in the way beamforming

    Suppression of a signal reflected from the underlying surface is being performed for the cause of location of the low-lying objects. Since the spectral characteristics of the signal and noise match, spatial difference is formed by oblique irradiation. Spatial differences are allocated by the radiation pattern. The suppression is performed by forming the zero value in the equivalent radiation pattern. The equivalent radiation pattern is a section of a generalized ambiguity function of the signals. The graphs of equivalent diagrams are shown for several areas of suppression in the view sector. The adaptive system is performing the equivalent radiation pattern zero-value scan of the underlying surface in the view sector. These algorithms are successfully applied to the MIMO system. A feature of the MIMO system is spotted in the task of forming zero values of the equivalent radiation pattern.  

    Keywords: MIMO, underlying surface, ambiguity function, adaptive system, passive noise

  • 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

  • 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

  • Service as a markering and logistics category

    In the article was shown the essence of the concept of "service" from the standpoint of marketing and logistic activities, the service dualism, the assessment of service of marketing and logistic positions. In the article was made an attempt to differentiate service operations to marketing or logistics activities in the aim of improving the management process of customer service and competitiveness of the company

    Keywords: service, service management, logistics service, marketing service, service assessment

  • Evaluation of geological hazards and risks of the Eastern Donbass agglomeration

    To the East Donbass agglomeration has developed thematic maps of subsiding soils, indicating their capacity, groundwater levels, surface subsidence above mining, landslide and erosion hazards. Sources of information were the materials of the geological surveys, maps and literature data, and numerical modeling. For the purposes of industrial and civil construction built the final map of the cumulative effects of geological hazards.

    Keywords: geological hazard, modeling, geofiltration,subsidence, landslides, erosion, underflooding, agglomeration.

  • Zoning of territories as the mechanism of real estate management

    Zoning of territories is one of the mechanisms of real estate management. Economic analysis of real estate includes consideration of the problems of spatial – economic development of real estate which exists in specially organized space. Difference in land value, expressed through economic parameters of real estate, forms the basis of territorial – economic zoning, definition of cost equivalent of real estate objects. Global practice shows, that it is increase of land value as a result of zonal-territorial policy realization that leads to the maximal economic benefit. Only joint influence on real estate objects and their spatial environment сan provide the best social and economic results.

    Keywords: Zoning of territories, real estate management, economic analysis, zonal-territorial policy realization, spatial – economic development of real estate

  • The model predictive control system simulation for the catalytic cracking process of oil

    The especially the functioning of fluid catalytic cracking plant are considered. A mathematical model of a catalytic cracking plant is presented here. Implemented model identification based on experimental data. The predictive controller based on predictive control method for dynamic processes is developed. Effectiveness of the approach is confirmed by the results of catalytic cracking plant simulation. 

    Keywords: catalytic cracking, modeling, model predictive control, multivariate control system, optimization

  • Simulation re-routing strategies for the CBD network of Rostov-on-Don.

    This paper presents the results obtained at simulation of various algorithms dynamic route guidance. A simulation experiments has been executed for the CBD network of Rostov-on-Don with using AIMSUN package. The main objectives of research are estimate routing strategy and relation between shape of the macroscopic fundamental diagram and traffic assignment on the network.

    Keywords: re-routing, rate, dynamic traffic assignment, traffic conditions