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  • Optimization of factors affecting the efficiency of processing of foam concrete mixes by variable electric field.

    The optimization of the factors affecting the efficiency of Electro-activation of foam concrete mixes is carried out. For this purpose was applied mathematical planning experiment. As varied factors adopted grain size of sand grains, the value of the applied voltage and the duration of treatment. The mathematical models for strength, high density and structural quality are obtained.

    Keywords: Variable electric field, foam-concrete mix, coefficient of structural quality,

  • Study of the catalytic ability of the nanosized catalysts based on CeO2 during catalytic reaction

    The nano-catalyst ceria (CeO2), activated by Pt nanoparticles, is known for being prospective and efficient material widely used in catalysis, fuel elements, and sensors. One of the most up-to-date methods of catalysts' reasearch is X-ray absorption spectroscopy (XAS) that is sensitive to the chemical state of catalyst's active centers [1,2]. Using XAS in the fluorescense detection mode at CeL1 line with high precision we studied electronic structure of Pt-activated nanoparticles of ceria at various redox conditions. In order to detect partial X-ray fluorescence yield the emission line CeLγ3 was used, which allowed us to increase spectral resolution. We researched local atomic and electronic structure of the materials under study. Oxygen vacansies were found to appear on the nanoparticles surface of ceria at 5% CO He atmosphere. Theoretical modeling of the obtained spectra at CeL1-edge demonstrated good agreement with experiment.

    Keywords: X-ray absorption spectroscopy, HERFD, XAS, Ce-based catalysts, oxygen vacansies

  • Determination of the roughness and Chezy’s coefficients for calculating wastewater networks in conditions to reduce the cost of wastewate

    In conditions of reduction of the costs of wastewater actual value of the minimum speed and current case does not provide the required conditions of self-purification of networks. The studies conducted on the silt areas of current collectors of various diameters made of various materials with the purpose of determining the resistance of precipitation in the trays pipes.
    Describes the methodology and instruments of research. The data obtained allowed with sufficient certainty have established roughness coefficient bottom sediments of sewers.   

    Keywords: drainage network, the rate of self-purification, sewer, roughness, bottom sediments.

  • Calculation of the deformed condition of the block of a compound design from a hexagonal plate and a circular cylindrical cover under the influence of any loading enclosed in all its tops

    Article is devoted to strength calculations of compound designs. The deformed condition of the block under the influence of any loading enclosed in all its tops is considered intense

    Keywords: plate, shell, the strength, the composite structure

  • Algorithm and results of the numerical estimation of the effective mechanical properties of double-layer rubber-cord composite

    "The mechanical properties of the rubber-cord composite in strengh analysis are described. There is an algorithm of the numerical estimation of the effective (average) properties of the rubber-cord. The effective properties are defined by the successive application of different deformations to the representative volume of the rubber-cord composite (tensions along each coordinate axis and shifts in each cooridinate planes). The effective properties are defined in form of the generalized Hooke's law (for anisotropic materials). A serias of computations in estimatition of the effective properties of double-layer rubber-cord composite was carried out based on the proposed algorithm. The dependence of the effective elastic modules of rubber-cord on the angle of cord was explored. The according graphs are represented in the article."

    Keywords: theory of elasticity, effective properties, strength analysis, rubber-cord, numerical modeling, finite element method, CAE FIDESYS

  • Increment borer and ways for its improvement

    The article represents the description of the construction of increment borer, its present modifications and additional devices. On the basis of the conducted survey the authors of the article defined the ways for improvement of the borer. Suggested technical solutions are at the stage of patenting  

    Keywords: Increment borer, preparatory works of forest logging, tree age, forest inventory, core.

  • Potential of combination of wood barking and branches cutting within through technologies of timber industries

    The possibility of combination of wood barking and branches cutting within through technologies of timber industries is shown. Comparison of several such processes is made with the use of functional-technological analysis and hypothesis of expediency of creation of the process technology and equipment for simultaneous group wood barking and branches cutting is formulated.  

    Keywords: barking, branches cutting, through technologies, woodworking, timber industry

  • 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

  • A simulation of small scale helicopter using position-trajectory regulator

    In this paper, the synthesis of a trajectory regulator for a mini-helicopter are described. We propose a method to hardware-in-the-loop simulation using simulator AerosimRC. The simulation results are showed. The tasks for the application of the method are pointed.

    Keywords: position-trajectory regulator, helicopter, mathematical modeling, simulation, algorithms.

  • The design's technique of combined drills with replaceable multiface plates

    The technique of the geometrical analysis and the analysis of force loading of combined drills with the replaceable multiface plates is offered in this work. This technique is allowing to determine geometrical parameters and specific force loadings in each point of a plate’s cutting edge taking into account its orientation in the drill case. Application of this technique allowed to establish the reasons of the drill’s low durability. The offered technique allows to design drills from the minimum unbalanced radial component of cutting force which increases its working capacity and the processed holes quality. New designs of combined drills both with two, and with three replaceable multiface plates are offered in this work. The durability of this new drills is increased by the plates mutual turn for the minimization of an unbalanced radial component of cutting force  

    Keywords: combined drill, replaceable multiface plate, drilling, design, equilibration, geometrical analysis, the analysis of power loading

  • 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

  • Localization of damage concrete structural elements with prestressed reinforcement

    The possibilities of the vibration method changes the curve oscillation localization damage concrete structural elements with prestressed reinforcement. This article discusses a method for curve oscillation example concrete slab in terms of spatial, complex stress state under the action of vertical force Q.

    Keywords: Vibration diagnostics, fault detection, diagnosis, design, construction span, reinforced concrete, concrete, reinforcement, prestressing.

  • 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