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  • Diagnosis of a piezoceramic element based on the active component of conductivity

    An estimate of the frequency discretization interval was obtained in solving diagnostic problems of a piezoceramic element by means of different methods based on measuring the active component of conductivity in a number of discrete points. This allows avoiding precision loss and, at the same time, reducing the number of measurements and computational operations.

    Keywords: Piesoceramic element, Q-factor, active component of conductivity

  • GPR determination of electrical and physical properties of motor road and railway structural layers

    The paper studies the possibility of quantitative processing of the GPR data for determining the dielectric permittivity and conductivity of a medium (soil samples). Experimental studies are made using radargrams of soil samples with specified values of moisture and conductivity. New methods of quantitative processing of radargrams are proposed in this work to determine the dielectric permittivity and conductivity of soils. The methods were successfully tested on various sections of Russian railways net.

    Keywords: layered road profiling, GPR, soil moisture, soil layers profiling, soil conductivity

  • Modeling the ab initio structure of layered aluminosilicates.

    This work deals with the study of atomic and electronic structure of kaolinite samples (Glukhovtsy deposit) and montmorillonite (Millerovsky deposit) by density functional theory. The applicability of existing exchange-correlation potential in the local density approximation (LDA) and the generalized gradient approximation (GGA) is analised for an adequate description of the physical properties of layered aluminosilicate. An experimental and theoretical study of the IR spectra of minerals, as well as the identification of the most intense absorption bands, performed in the approximation of DFT using the exchange-correlation potential PW91. The analysis of the band structure of these minerals, which showed that these compounds are direct-gap insulators.

    Keywords: DFT, clay, clay minerals, phyllosilicates, atomic and electronic structure, crystalline systems, IR spectrum band strukutra, the electron density

  • The ratio of particles sizes in polydispersed structures as the first step to the optimization of composite binding compounds

    Calcating-experimental method shows that on the basis of cement and fine-grounded mineral powder, complex binding materials can be obtained, providing high strength of obtained stones.

    Keywords: cement, mineral powder, components, optimization, strength

  • Complex research of the composition and structural characteristics of the rock-forming minerals in Millerovsky bentonite clay

    This work deals with the integrated study of the composition and structural characteristics of the rock-forming minerals in Millerovsky bentonite clay. The qualitative and quantitative analysis of the clay samples is made by X-ray diffraction , X-ray photoelectron spectroscopy and thermal analysis . The morphological and microstructural features of minerals are investigated by scanning electron microscopy. The application of the method of direct theoretical calculation of the diffraction patterns is showm to determine the crystal-chemical parameters of the studied minerals. The results are aimed at explaining a number of physical and chemical properties of layered aluminosilicate.

    Keywords: clays, clay minerals, layered silicates, x-ray diffraction, crystalline systems

  • Development of a framework enabling technology waste rock and minerals processing ores KMA

    The problem of utilization of iron ore tailings . The prospects of iron ore mining in the Russian underground . A method for extracting iron from tailings to 9 % of the original content, by mechanochemical processing. The results of particle size distribution , chemical and mineralogical analyzes of samples collected waste ferruginous quartzites LGOK . Experiments were carried out using the methods of planning optimal experiments , Box-Behnken and included 24 experience. Obtained according to the content of metal recovery in the leach solution of sulfuric acid , sodium chloride , rotor speed and the ratio of disintegrant liquid and solid phases. This dependence allows to determine the optimal parameters of technology in terms of " metal recovery ." The resulting secondary processing of tailings to be used in the manufacture of hardening mixes for stowing as an inert filler and binder counterpart .

    Keywords: tailings, mechano-chemical activation, iron ore, ferruginous quartzites, metal recovery

  • Comparative analysis of porous piezoceramics modelling by effective moduli and finite element methods with experimental data

    The results of computational experiments to determine the characteristics of the porous piezoelectric ceramics based on the methodology, including the effective modules method, simulations of representative volumes on a simple random method and the method of Witten-Sander, finite element method to solve static piezoelectric problems for heterogeneous composite media and the accounting of inhomogeneous polarization near the pores are presented. A comparison of the results of computer simulation with the known experimental data for the porous material PZT-4 and its analogs is realized. It is concluded that the accounting of inhomogeneous polarization in the vicinity of porous provide the better agreement between numerical results and large number of known experimental data. Thus, for most effective constants the smallest errors are obtained for a representative volume of the porous piezoelectric material, constructed by Witten-Sander method.

    Keywords: piezocomposite, porous piezoelectric ceramics, inhomogeneous polarization, mathematical modelling, models of representative volumes, finite element method, effective moduli

  • Researching a profile of potential of an electrostatic field during a blizzard in the Alp zone as potential renewable micro power source

    Tendencies of technological improvement of electronic chips led to reduction of their sizes, weight, development of functionality and decrease in power consumption. It allows us to discuss questions of developing renewable micro power sources which can provide power supply of autonomous microelectronic and micro circuitry systems for charge indication, paying attention to snow transfer, etc. 
    The purpose of the paper is researching a profile of electrostatic field potential in the mountain district which was estimated as a possible use as a renewable micro power source.
    It is found out that on windward sides of snow relieves the potential of electrostatic field exceeds three times to a similar  indicator for lee sides and is 80 V.  The potential is 3,5kV on polymeric surfaces (Nylon, teflon).   

    Keywords: snow storming electricity, electrization, potential of electrostatic field, charge, the salting, the loaded particles of snow, innovation electronics, micro circuitry, renewable micro power sources.

  • System approach to monitoring of a technical condition of buildings and constructions

    In article the safety mechanism in construction is shown. Main types of monitoring of unique buildings and constructions are opened

    Keywords: risk, construction, monitoring, labor protection, safety

  • To unstable coloration centres in rear earth gallium garnets

    The coloration centres (CC) in crystals of rear earth gallium garnets (REGG): Gd3Ga5O12 (GGG), Gd3Sc1,6Ga3,4O12 (GSGG) и Nd3Ga5O12 (NGG) obtained by Chohraljskiy method, were investigated by methods of optical spectroscopy and spectral analysis in the wavelength range of 0,2-0,87 microns. In the case of keeping the samples under dark conditions, unstable CC were formed in the crystals of GGG and GSGG. The absorption maxima are at λmax1 = 0,243 m and λmax2 = 0,275 m at concentration of N ~ 1018 cm-3. It is suggested that the observed enlightenment is caused by the recharging of growth defects and occurring the energy levels in the band gap of garnets. It appears that these CC correspond to centres of O- holes, originated from gallium vacancies V3-Ga 3+ in tetrahedral and octahedral nots which form near clusters of [V3-Ga 3+ - V2+O2- ]

    Keywords: color centers, rare earth gallium garnets, kristylly, Czochralski method, the crystal lattice

  • The influence of basic chemical composition on the properties nickel-zinc ferrites, received by radiothermic sintering

    To date, the main method of mass production of advanced functional materials for various purposes is the ceramic technology. In the manufacture of multi-component oxide compounds using of ceramic technology is difficult to achieve high uniformity of chemical composition. For activation of the raw ingredients and make it more uniform use of chemical-tions (co-precipitation of salts or hydroxides, spray drying, Cryochemistry) and physical-tions (mechano-chemical, microwave, ultrasonic) methods. The paper presents the results of work on obtaining Ni-Zn-ferrite 2000NN radiation-thermal sintering. The influence of base composition and alloying additions on the electromagnetic properties of the ferrites. Confirmed the effectiveness of the use of surface-active additives To increase the density of the raw pieces and level parameters. We propose a model that explain schaya efficiency of dopants in the radiation-thermal sintering.

    Keywords: Nickel-zinc ferrite, radiation thermal sintering, base composition, alloying additives, permeability

  • Panoramic image stitching with handling the parallax effect for the known world model

    The short review of existing panoramic systems are given. The limits of such systems doesn't allow to form a panoramic video with dealing the parallax effect in real-time systems. The presented algorithm for forming a panoramic video is free of these disadvantages. An algorithm based on mathematical model of the round-view system that takes into account the location of cameras, their intrinsic parameters and model of the world. The algorithm includes following chain of coordinate transformation: from panoramic image coordinates to spherical coordinates and to Cartesian world coordinate system, from world coordinates to camera coordinate system and to input image coordinates. Geometric distortion of camera is dealt. Model of the world is represented as spherical and a hemispherical surfaces.

    Keywords: panoramic image, round-view video system, camera model, camera distortion, parallax

  • Effect of additives on the properties of the alloy radio-Mg-Zn-ferrite obtained by sintering heat-radiation

    Promising absorbing materials along with a Ni-Zn-ferrites are Mg-Zn-ferrites, as they are also intensively absorbs electromagnetic waves in the frequency range from 50 MHz to 1000 MHz. The main advantage of the Mg-Zn-ferrite is used as an inexpensive raw material magnesium oxide. The paper presents the results of research to improve the efficiency of broadband radio-magnesium-zinc ferrite by increasing the contribution of the dielectric loss. The influence of alloying elements of the atmosphere gas and cooling after the sintering thermal radiation by absorption of electromagnetic waves. Confirmed cooling efficiency of products after sintering in an atmosphere with reduced oxygen partial pressure to increase the dielectric constant. A model is proposed to explain the increase in the dielectric loss ferrite during cooling in a reducing atmosphere.

    Keywords: radioabsorbing ferrites, microstructure grain boundaries radio measurement radiation thermal sintering

  • The analysis of emergencies on linear part of the main gas pipelines.

    In article statistical data on failures on a linear part of the main gas pipelines are presented, the reasons of their emergence are defined. Standard scenarios of development of emergencies are provided, and also the basic principles of determination of frequency of emergence of failures are shined.

    Keywords: accident, analysis, diameter, linear part of the main gas pipelines, depressurization, scenario, pipeline.

  • Applying the criterion of strength balance in designing replaceable inserts of cutoff and grooving tools.

    The issue of increasing the strength of cutoff and grooving tools is considered in the paper. The principle of strength balance of edge is offered to be used in designing the replaceable inserts. The calculations are made and the shape is designed for the strength balanced front surface of the cutting tools. The analysis of the received data is made and the regularities of the designed shape of the front surface of the cutting edge are established. Designs of replaceable cutting inserts made with a glance to structural characteristics and operating conditions of the cutoff and grooving tools are offered.

    Keywords: strength, cutting end, strength balance, cutting end, cutoff tools