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  • Solid-state synthesis of copper-containing zeolites: local atomic structure of catalytically active copper centers by means of XAS spectroscopy and DFT modeling

    Today, catalysts based on zeolites containing transition metal ions are being intensively developed, ensuring the selectivity of the reaction of direct oxidation of methane to methanol. In current work, the X-ray absorption spectroscopy complimented with the structural models obtained in frames of the density functional theory were used to study the dependence of the local atomic structure of copper centers in mordenite type zeolites synthesized by solid-phase ion exchange using CuCl and H-MOR, upon the annealing temperature at different stages of synthesis. The typical Cu – O interatomic distances and the corresponding coordination numbers are determined. The dependence of the fraction of copper ions on the zeolite on the annealing temperature was established.

    Keywords: EXAFS, DFT, zeolites, solid-phase synthesis, methanol synthesis

  • Calculation of the main beam of the production building

    The problem of calculating rods for vector perturbations consisting of five components is solved: 1. kinematic transverse vibrations of the left end; 2. kinematic transverse vibrations of the right end; 3. dynamic bending moment at the left end; 4. dynamic bending moment at the right end; 5 dynamic uniformly distributed lateral load along the length of the rod. The transfer functions from each disturbance are obtained separately. Using these functions, we obtained the elements of the spectral matrix for stationary random processes, taking into account their correlation. The most common types of processes are considered: exponentially correlated random process; process with latent periodicity (with characteristic frequency); truncated white noise. The formula for obtaining the dispersion of displacement of sections is shown.

    Keywords: rod, harmonic oscillations, natural frequency, kinematic disturbances, dynamic disturbances, transfer function, correlation matrix, random process, delta-correlated random process, latent periodicity, truncated white noise

  • Technological recommendations for repairing kamaz power booster

    When developing any technology of repair it is necessary to conduct research mikrolitrazhnyh worn parts of assemblies using metrological equipment. At the moment to improve the accuracy of research the repair company should use the latest measuring system, allowing to carry out a full complex of works on profileration surfaces of worn parts. Such devices include for example profilograph profilometer English company "Taylor Hobson", which allowed to determine the amount of allowance for machining the body of the power steering distributor. As a result, using the data obtained, the technology of repairing the power steering of KAMAZ vehicles was developed.

    Keywords: metrological equipment, profilograph-profilometer, micrometer, power steering, repair technology, recovery, wear, distributor, shaft

  • Best available techniques of decrease dust emissions into the atmospheric air applicable in various industries

    The article provides an overview and analysis of the best available techniques (BAT) for reducing dust to the atmosphere from enterprises of various industries (mining, fuel industry, ferrous and nonferrous metallurgy, building, livestock production). Dust has the property to settle and adsorb, affects the state of the environment and human health. These factors determine the importance of introducing dust reduction technologies. Methods generated applicable and branch, as well as the main factors limiting the applicability of technologies. Recommendations proposed to improve the implementation of the best available techniques.

    Keywords: atmospheric air, dust, best available technique, industry, dust removal equipment

  • Fibrobenfo phobet with dispersed polyarmirovany

    Fibroenothobetons with the use of sawing volcanic tuff were investigated. The compositions of fibropenot phobetons with the use of nylon and basalt fibers have been developed, which allow to significantly reduce shrinkage deformations and increase the strength characteristics of foam phobeton. The maximum increase in compressive strength by 38% and during bending by 110% is observed in samples of fibroenophoto concrete with a reinforcement of 0.6% by volume with basalt fibers. The combination of nylon and basalt fibers is more effective for reducing the shrinkage of foam photon concrete compared to mono-reinforced samples.

    Keywords: portland cement, tuff sawing waste, Neopor 400 frother, nylon and basalt fiber, polyheating, foam concrete, fibroenote sand concrete, bending and compression strength, shrinkage

  • Development and computer simulation of AC voltage regulator

    Development of electric energy converters with high energy characteristics is an important scientific and technical task. The solution of this problem is impossible without the use of modern methods of computer modeling. To improve the quality of electricity, filter-compensating devices are used. Develop converters with good energy performance. In this paper, we developed a computer model and circuit of the AC voltage regulator with high-frequency pulse modulation of the output voltage. Methods of digital signal processing and computer simulation are used. In the environment of the software product MATLAB, a program synthesizing the form of voltage at the output of the AC voltage regulator. The program uses a variety of algorithms to control the power keys of the AC voltage regulator. The results of harmonic analysis of the output voltage of the regulator are presented. The study of the AC voltage regulator circuit is performed in the environment of the ORCAD software product. The work of the scheme on the active-inductive load is considered. Electromagnetic processes occurring in the circuit of the AC voltage regulator are investigated. The optimization of the scheme elements is performed. Time diagrams of currents and voltages are obtained. The results of computer simulation can be used in the development of electrical energy converters for electrochemical and electro thermal production.

    Keywords: computer simulation; AC voltage regulator; algorithm; high-frequency pulse modulation; time diagrams; transistor key; control system; harmonic composition; damping circuit; thyristor; active-inductive load

  • The change in the dynamic modulus of elasticity of sound-insulating gasket of mineral wool materials in the construction of a floating floor in time

    The article discusses the dynamic characteristics of mineral wool materials (dynamic modulus of elasticity and stiffness, reduced dynamic stiffness) and the effect on them of porosity and relative deformation of the material. The main objective of the study is to determine the value of the dynamic modulus of elasticity, taking into account its change with time under the action of a long-term static load for calculating the impact noise insulation.

    Keywords: mineral wool material, dynamic modulus of elasticity, strength of parts of a structure, sound insulation, ultimate states, construction

  • Propagation of hf radio waves in the polar ionosphere during periods of amplification of magnetospheric convection concentration

    In the framework of simple volumetric models of electron concentration in the F layer of the polar ionosphere, the influence of non-stationary convection on the state of radio paths in high latitudes is considered. Calculations of three-dimensional trajectories of HF-radio beams showed a significant difference for quiet and disturbed conditions

    Keywords: ionosphere, refraction, convection, plasma, radio beams, high latitudes

  • Development of metal-ceramic composite material for the friction unit of the absorbing apparatus of the railway car

    The absorbing apparatus serves to extinguish the impact when the wagons cohere and move. Most of the energy, about 80%, in this system is absorbed by a friction unit consisting of a friction wedge and a fixed plate. Absorption of energy in this system occurs due to the work of frictional forces arising during longitudinal motion of the pressure wedge with respect to the friction plate. Due to the large shock-frictional loads, intensive wear and destruction of the cermet cake occurs, which adversely affects the energy capacity of the absorbing apparatus. To eliminate these shortcomings, studies were conducted to create a new material. After numerous experiments, a composition was obtained with the optimum content of components, which maximally satisfies the working conditions of the friction unit and the requirements imposed on these devices.

    Keywords: absorbing apparatus, friction unit, cermet, wear resistance, friction plate, powder material, sintering technology

  • On the possibility of detecting viruses with an optoacoustic method using carbon nanoparticles

    The possibility of detecting viruses in biomedical research using the optoacoustic method with carbon nanotubes is considered in the paper. In this paper, we consider the setup used to detect optoacoustic responses from a sample, which allows the recording of optical-acoustic signals generated by carbon nanotubes attached to the surface of viruses in the blood and which have high optical absorption. When the sample is irradiated, the absorbed energy from the laser radiation is converted into kinetic energy by means of energy exchange processes. This leads to local heating and, consequently, to the appearance of a wave of sound pressure. By recording ultrasonic waves, it is possible to form a spectrum of the optoacoustic signal for the test sample, which can be used to detect the absorbing components in it.

    Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

  • Layered two-dimensional-periodic absorbing structure of the optical range

    Described trends in the application of two-dimensional-periodic absorbing structures in optical and THz range. The results of calculation of the scatter and reflection of multilayer structures. Designed optimal parameters of the structures to monitor the greatest effect absorption.

    Keywords: resonant absorption, plasmons, reflection coefficient, diffraction gratings, periodic structures

  • The method of using the basic equation of passive location in the calculation of coverage areas on protected objects of information

    Passive detection sensors are widely spread in engineering-technical systems of information protection. During designing such systems, it may be difficult to calculate the coverage areas of infrared detectors. This is due to the fact that the problem of establishing a relationship between the theory of statistical detection and the choice of parameters for the equation of the maximum detection range is not considered in detail. In this regard, the task was to develop a method for applying the basic equation of passive location to calculate the coverage areas of infrared detectors. The calculation method is developed on the basis of the equation of the maximum range of the passive receiver. The study considered three models of the signal-to-noise ratio: a signal against a white noise background with fully known signal-to-noise parameters; detection of a signal whose phase and amplitude are unknown; and detection of a random signal against a noise background. As a result of the research, the conditions under which the passive signal detection formulas on the background of noise give correct results were found. Thus, the connection of the statistical theory of detection with the equation of the range of the passive emitter was established.

    Keywords: information security, infrared detector, passive location, engineering and technical protection, the pyroelectric element

  • Calculation of the graphene gratings electrodynamic characteristics.

    Diffraction characteristics of the gratings are calculated by two methods - method of approximate boundary conditions and a strict method based on the numerical and analytical solution of the two-dimensional integro-differential equation. Results of the graphene diffraction gratings calculations are presented.

    Keywords: graphene, graphene gratings, volume integral equations, plasmons, coefficient of reflection

  • Investigation of mathematical methods for identifying bearings of unmanned aerial vehicles in a group

    The problems of studying the mathematical interpretation of the results of trajectory measurements in terms of increasing the accuracy of identification of bearings of unmanned aerial vehicles during their movement in the group "swarm" and "system" are discussed. The variants of identification of horizontal (IHP) and spatial bearings (PPI) are proposed both separately and in a complementary application. Identification of bearings of similar objects in the swarm type group is expedient to be carried out according to the IGP-IPP algorithm. However, it is only partly operational at distances of 3 km or more. As the main algorithm for identifying bearings of similar objects in the "Story" group, it is advisable to use IPP. Although these algorithms achieve high identification efficiency under favorable conditions, with tougher conditions, they drop rather sharply. Therefore, to maintain a high level of probability of "pure" identification, it is advisable to use additional measures to combat false triads. For the removal of problems, it is necessary to develop and apply combinatorial algorithms for exhaustive search, which is the direction for the development of further research.

    Keywords: unmanned aerial vehicle, group of objects, bearing identification, horizontal bearing, spatial bearing, identification criteria, false notch

  • Teploognezashchitnye composition cement mortar on the basis of the distended vermiculite and the pumice

    Are represented the results of studies on the development of teploognezashchitnykh composition cement solution mixtures on the distended vermiculite and the pumice with the application of a multifunctional additive D -5. Are proposed the compositions of teploognezashchitnykh composition mortars, which make it possible to substantially improve the physicomechanical properties of solution mixtures and solution. The introduction of multifunctional additive D -5 to solution mixtures makes it possible to improve the properties of composition solution mixtures and to improve the characteristics of solution. The replacement of the fine dispersed fraction of the distended vermiculite d0,63 mm does not produce by pumice by the volume in the solution mixtures a noticeable increase in solution density, in this case their strength characteristics grow. The developed composition solution mixtures correspond to requirements ALL-UNION STATE STAN. 28013–98 and have low prime cost due to the use of the pumice

    Keywords: portland cement, the distended vermiculite, pumice, additive D -5, teploognezashchitnyy composition solution, transverse strength and compression, the mobility of mixture, exfoliation property, the density