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  • Physical and mathematical sciences. Physics

  • Green nanostructured biodegradable materials Short Review Part II

    The article presents abrief overview of the work in producing and studying of environment friendly nanostructured polymeric composites. Preparation technology and main applications of the nanocellulose (NanoCell) is described. Novel environment friendly hydrophobic polymer composites were developed. These compo¬sites consist of a thick layer of cellulose substrate and a thin protective layer of a biodegradable polymer. Various types of the layer composites and their applications in production of packaging materials are described. The proposed biodegradable nanocomposite coating increases strength of the natural packaging materials and serves effective barrier against water and grease. Wastes of the novel polymer materials can be utilized in two ways: by repulping and by biodegrada¬tion. Widespread usage of the proposed polymer compo¬site materials will bring about an improvement in the ecological state of the environment. Method for preparation of the reactive nanocellulose biocarrier and discussion about its biomedical and cosmetic applications are described as well.

    Keywords: : nanocellulose, biocarier, biodegradable materials, nanocopmosite polymer coating, packaging materials , ecological safety

  • Method development for calculation of temperature and thermoelastic fields during sapphire growth

    The author presents the method of calculation of temperature and thermoelastic fields during sapphire crystals growth by horizontal directed crystallization method. Realization of the offered technique allows to carry out the analysis of changes of the temperature and thermoelastic fields in the crystal taking into account spatial and geometrical characteristics of heaters by means of computing experiment. On the basis of the analysis we can carry out redistribution of defects in sapphire, and increasment quality of the grown crystals.

    Keywords: sapphire, temperature fields, thermoelastic stresses, horizontal directed crystallization method, technique, computing experiment

  • Research of abrasive treatment influence on process of defects formation in sapphire crystals

    Results of research of abrasive treatment influence on process of defects formation in sapphire crystals are presented in article. On the basis of the received results recommendations about determination of properties of sapphire near-surface layers and about improvement of crystal quality are developed. Researches of influence of abrasive treatment on process of defects formation in sapphire crystals allow to choose the optimum modes of process of receiving sapphire monocrystals products.

    Keywords: sapphire, abrasive treatment, defect, optimum mode, crack, near-surface layer, grinding, polishing

  • Research of plastic properties of the heated porous powder-like materials at tests on a bend

    In the article information is presented about plastic properties of the heated porous powder-like materials from ferrous powders at tests on a bend. Dependence of tangential eτ, radial eρ is set and transversal ez deformations from initial porosity of standards and grain-size distribution. Experimental confirmation of hypothesis of flat sections and unchanging position of neutral surface is got at the bend of the heated porous standards.

    Keywords: plastic property, heating, porous powder-like material, bend, tangential deformation, radial deformation and transversal deformation

  • Thermal processes at superficial plastic deformation of titanium alloys

    The theoretical determination of the temperature in the contact area in the rolling ball and ultrasonic hardening of titanium alloys OT-4, VT6 and VT9. It is shown that as a result of deformation, and the work of the friction forces is formed of heat. At the same time the total temperature field is influenced by the geometric parameters of the items to be treated, during previous processing, the total thermal power sources and the nature of the heat exchange with the environment. A generalized solution of the maximum contact temperature at the ball rolling and ultrasonic hardening by moving sources.

    Keywords: ultrasound, hardening, roll forming a ball , the contact area, a titanium alloy .

  • Electrophysical properties of polyalkaline oxide tungsten bronze powders

    The data of experimental research of electrical conductivity and thermoelectric power of superfine powder of nonstoichiometric polyalkaline oxygen bronzes Mx'My''WO3 was established. Electrical conductivity of tungsten bronzes in thermocycles in 295-745K (vacuum) was studied. It will be observed that the bronzes after thermotreatment are semiconductors of n-type. Also the rise of electrical conductivity of powdery sodium, potassium bronzes in tens time was found. In their conditions the maximum value of electrical conductivity had bronze Na0.7WO3. Characteristic properties of mutual influence of nonstoichiometry of tungsten suboxides and chemical compositions, electrophysical properties of polyalkaline tungsten bronzes was established.

    Keywords: electrical conductivity, polyalkaline oxide tungsten bronzes powder, thermoelectric power, nonstoichiometry, tungsten suboxide

  • Management properties of PZT piezo-ceramic material used in sonar radiating elements

    Piezoceramics phases of (1-х)PbTiO3-xPbZrO3 is the basis of most high-performance piezoelectric materials. Electrophysical and mechanical properties of these materials can be varied over a wide range by varying the composition and by processing methods: the methods and modes of sintering conditions polarization. Topical to study the influence on the properties of PZT materials processing methods at the stages of manufacturing piezoelectric samples. In the role model of the object has been selected multicomponent system PbTiO3-PbZrO3-PbNb2/3Zn1/3O3-PbW1/2Mg1/2O3-PbSb2/3Mn1/3O3. Samples of piezoelectric elements for the study were obtained in two ways: in the first case, the sintering samples was carried out by the usual ceramic technology, and in the second by hot pressing. The grain structure was formed in both cases in the presence of the glass phase, the quantity of which decreases with increasing temperature, while in the first case, an increase in the velocity of the secondary recrystallization, and in the second of its suppression. It was found that regardless of the technology of the samples εT33/ε0, d33 and VЕ1 at high temperatures, due to the increase of grain and coercive field, which complicates the process of polarization. Maximum values εT33/ε0, d33 and VЕ1 samples prepared by hot pressing at 10 - 15% higher than if received by conventional ceramic technology.

    Keywords: Piezoelectric ceramics, doping, combination, pezophase, piezomaterial

  • Theoretical work basis and design philosophy of highcurrent coaxial type termoresistors

    Thermoresistors nowadays are used not only as parts of temperature sensors and flowmeters but they are used as components of starting and control devices. Use of low-powered thermoresistors as starting and control devices parts needs a lot of devices that reduces equipment reliability. Current step-up running through motor-starting devices simplifies control circuit. For using thermoresistors in electric circuits with high-discharge rate it is necessary to use special constructions in order not to let termoresistor body be overheated. Thermoresistor expansion results in changing of thermal fields distribution pattern inside this semiconductor. The authors show calculated characteristics which let determine proportions and shapes of semiconductor subject to thermoresistor temperature.

    Keywords: high power thermoresistors, thermoresistors of coaxial type, current density, temperature, analogy criterion, thermal conductance, temperature gradient, thermal field, stability criterion

  • Analysis of ways of increase and criteria for evaluation of stability of the welding arc category

    In article the analysis of ways of increase and criteria for evaluation of stability of the welding arc category is carried out. The most perspective way of increase of stability of the arc category, can be carried out due to pulse, high-frequency impact on a welding contour. The experimental data obtained at research of the combined power supply system of the arc category of a direct current at parallel connection to the main welding power supply of the additional generator of impulses are given. Influence of a pulse component from the additional generator with a frequency of 40 kHz, on stability of burning of the arc category is considered at manual arc welding by the covered electrodes. As criteria for evaluation of stability of burning of the arc category have been accepted such as, the explosive length of an arch with which there is it's natural break and coefficient of stability. The conducted pilot studies and positive results of skilled approbation of the developed power supply system of the arc category allow to recommend it for application at installation of responsible metal designs.

    Keywords: Stability, the welding arc category, welding by the covered electrodes, pulse impact on a welding contour, explosive length of an arch, stability coefficient, the electromagnetic field, the generator of impulses

  • Hot powder material, dope the ferrotitanium, based MXA chip D16, its structure and properties

    Considered hot-powder materials obtained by the joint mechano-chemical activation of chips D16 ferrotitanium powder in a medium saturated aqueous solution of boric acid with the addition of aluminum powder. The technology includes: mechanochemical activation composition; cold pressing; heating in air, and hot stamping. Investigated the mechanical properties and structure of the obtained hot-materials. Advanced technology allows to obtain a material with high values of strength and hardness.

    Keywords: mechanochemical activation, milling, chips D16, ferrotitanium, hot-powder materials, agglomeration

  • Investigation of diffraction of electromagnetic pulse on the slots Fresnel screen system

    The problem diffraction H-polarized electromagnetic pulse is reduced to the solution of the integral equation. Singled and analytically transformed into a special part of the integral equation. It transformed the integral equation applied collocation method for solving the spatial coordinate. Found near field and the results of calculations of diffraction of electromagnetic pulse.

    Keywords: Fresnel diffraction, electromagnetic pulse, collocation method, a near field

  • Influence of thermochemical activation of hydrolytic lignin by hydroxide of potassium on properties of carbon adsorbents

    It was found that increasing the temperature of thermochemical activation of up to 750 °C and increasing the dosage of potassium hydroxide to 2.1 g / g of activated carbon (AC) synthesis of hydrolytic lignin has a positive influence on the formation of adsorption and structural properties of the AC.

    Keywords: thermochemical activation .potassium hydroxide , activated carbon, synthesis, hydrolytic lignin, formation, adsorption and structural properties

  • A comparison of the antiwear properties of water-organic solutions containing nano-sized particles of lead and palladium

    A promising direction of creation of new lubricants is their modification by nanoclusters of metals, which form in the zone of friction of the protective film, providing reduction of wear of friction pairs. In this regard, the aim of this work is to study tribological properties of lubricating compositions containing nanosized particles of lead and palladium. A lubricating composition was obtained in aqueous solution during electrolysis with a lead anode or in the presence of salts of palladium in an ultrasonic field (complex processing). Tribological studies showed that the lubricating compositions have high anti-wear and extreme pressure properties.

    Keywords: nanoscale particles, friction, wear, anti-wear and antiwelding properties

  • А сomparison of tribological efficiency of lubricating compositions containing nanoparticles of copper, lead and palladium

    Currently widely advertised and offered on the domestic and global markets: anti-wear additives to motor, gear, industrial oils. Developed a method of producing nanoclusters of copper, lead and palladium in water-alcohol environments and the possibility of realization of the effect of wearless friction when using such a lubricating composition to the rubbing steel surfaces. The studied tribological properties of metal nanoclusters in aqueous solutions of multinuclear alcohols with the use of mechanical friction machine AE-5.

    Keywords: nanoscale particles, friction, wear, wearless friction

  • Non-reflecting optical grating in the new plasmonic materials

    The present state and development trends of plasmonic materials. The results of the calculation of scattering and reflection diagrams nanostrzhnyah of ZnO. And the prospects for the use of anti-reflective optical lattices.

    Keywords: non-reflecting grating plasmonic materials, nanophotonics, nanostructures, reflectance

  • Hybrid epoxy-amine hydroxyurethane-grafted polymer

    Cured linear hybrid epoxy-amine hydroxyurethane-grafted polymer are preparedby novel structure with lengthy epoxy-amine chains, pendulous hydroxyurethane units and a controlled number of cross-links. These hybrid polymers combine increased flexibility with well balanced physical-mechanical and physical-chemical properties of conventional epoxy-amine systems and may be used, for example, for manufacturing of synthetic/artificial leather and sport monolithic floorings. US Patent Application 14/296,478, filed June 05, 2014.

    Keywords: linear epoxy-amine chains, hybrid hydroxyurethane-grafted polymers, synthetic nonisocyanate leather.

  • Features of the ruthenium oxide-titanium anodes in sodium chloride solutions of different concentrations

    The effect of sodium chloride concentration on the job ORTA electrodes. It is found that the electrodes OPTA, especially in the sodium chloride concentration below 50 g/liter, three groups occur conjugate processes, oxidation of chloride ions, the solid-phase oxidation of the anode material, dissolution of the active catalytic coating. The processes of oxidation of chloride ions prevail in current densities of 0.001 - 0.032 A/cm2 at high current densities become essential processes of oxidation of the ruthenium oxide coating. The oxidation of chloride ions, especially at concentrations less than 50 g/liter can be described as occurring in a constantly evolving anode active material due to its corrosion and solid-phase oxidation.

    Keywords: ruthenium oxide-titanium anode, sodium hypochlorite, polarization dependence, water disinfection, tafel dependence, oxidation of chloride ions, solid-phase oxidation of the anode material, changes in the activity of the anode material, anion ruthenate, an

  • Simulation design of silicon solar cells using the program PC1D

    Created single-stage model of silicon solar cell using PC1D v.5.9 program, designed to simulate the photovoltaic devices. In the process of simulation change the level of doping and thickness of the n + type layer of the front, as well as applied texturing the front surface. The influence of the doping level and the thickness of the n + type layer in the photovoltaic solar cell characteristics. It was determined that with the increase of the doping level and the thickness of the front n + -layer a decrease in the efficiency of solar cells. It was found that the use of texturing the front surface leads to an increase in efficiency and is associated with reduced reflection losses and an increase in the photocurrent.

    Keywords: Silicon solar cell thickness, doping levels, texturing, current-voltage characteristic

  • Technical science. Instrument making, metrology and information and measuring devices and systems

  • Radiophotonics amplitude-phase interrogation methods of complexed sensors based on fiber Bragg gratings

    The principles of construction of the interrogator for fiber optic sensors based on Bragg gratings, implementing radiophotonics measuring conversion technology on the principle of "optical wavelength - the amplitude and phase of a radio signal - measured value" are concerned. Their comparison with classical opto-electronic and radio photonic interrogator, implementing technology measurement conversion on the principle of "optical wavelength - radio frequency - the measured value" are produced. It is shown that the opto-electronic interrogator have significant limitations on resolution and interrogation speed and difficulty of simultaneous measurement of multiple, complexed to at least two measured values. Radiophotonic frequency interrogator, built on the basis of interferometers with additional dispersion conversion "rate - time" or optoelectronic oscillators allow to overcome the drawbacks of optoelectronic, but characterized by the complexity of the implementation of schemes of measuring conversion shift of the center wavelength of the grating in the information of unknown frequency. Radiophotonic amplitude-phase interrogator which is working at a known frequency - radio frequency envelope of the beat between the components of the two-frequency probe radiation signal, are proposed. This technique allows to exclude from the measurement process information search procedure of unknown frequency or amplitude of the maximum reflection of the FBG, which improves the speed and resolution of interrogation. Experimental results are presented to verify the procedure.

    Keywords: fiber optic sensor, fiber Bragg grating, optoelectronic interrogator, radiophotonika, opto-electronic oscillator, measuring conversion type "optical wavelength - the frequency of the radio signal - measured value", measuring conversion type "optical wavel

  • An algorithm for localization of optical structure disturbances in biomedical objects using time-resolved diffuse optical tomography

    Biological tissue optical structure disturbance localization algorithm for time-resolved diffuse optical tomography is described. The key features of the presented algorithm are: the initial approximation for the spatial distribution of the optical characteristics based on the Homogeneity Index (HI) and the assumption that all the absorbing and scattering inhomogeneities in an investigated object are spherical and have the same absorption and scattering coefficients. The described algorithm can be used in the brain structures diagnosis, in traumatology and mammography.

    Keywords: time-resolved diffuse optical tomography, localization of optical inhomogeneities, forward problem, inverse problem, homogeneity index

  • The system that automatically dials emergency services in the event of a road traffic accident

    The paper represent a view about modern solutions of operational notification of emergency services about Hard traffic accident and realisation of suitable software product.

    Keywords: mobile device, mobile application, medical ambulance, emergency reaction, means of the notification, electronic medical record, java programming, Android operating system, road accident, geodata, time, "gold" hour

  • Sensory passive optical networks and the key issues of fiber Bragg gratings application inside them

    The principles of construction of sensory passive optical networks, implemented the concept of the unified field of complexed fiber optic sensors and based on hybrid wave and time division multiplexing, are discussed. Their advantages in comparison with classical techniques of oneparameter multiplexing by time, wavelength, frequency, space, codes, etc. are shown. Prototypes and the structure of the sensory passive optical network with a hybrid wave and time division multiplexing are presented. The ability how to survey the point sensors, sensors of quasi-distributed and distributed types are defined, so as ability how to use the probing signals of pulse and continuous types. Especially the issues of similar probing of consecutive Bragg gratings using layered exclusion mechanisms (pulse sensing) and Q-factor measurement of the total envelope of the gratings spectrum (continuous amplitude-phase sensing) are explained. The requirements for the construction of sensory passive optical networks based on the hybrid wave and time division multiplexing in diverse parameters matching of Bragg gratings wavelength with multiplexers based on arrayed waveguide grating are presented. This requrements are based on the possibility of using the latter as support structures for interrogation of the first. Variants of the networks and their characteristics are presented.

    Keywords: unified field of complexed fiber-optic sensors, sensory passive optical network, the hybrid time and wave division multiplexing, pulse and continuous probing, fiber Bragg grating, arrayed waveguide grating

  • The shadow imaging of gas and plasma flow in an inductively coupled plasma optical emission spectrometer

    Dynamics of gas and plasma flow in a Fassel type torch for the OPTIMA 2000 optical emission spectrometer (PerkinElmer, USA) was investigated using the original shadow Toepler visualizer. Significant transient instability of plasma’s flow was registered by the high-speed shadow imaging. Observable structure of the plasma torch was described and interpreted. The process of formation of toroidal vortices within the plasma torch was demonstrated, its frequency was estimated. Effect of reverse gas flow back to the plasma torch is revealed, interpreted and experimentally validated. It is noted that ambient air containing residues of the analyzed substances getting into a spectrally pure analytical zone of the plasma torch can lead to deterioration of metrological characteristics of a spectrometer because of “memory effect”. A set of practical recommendations to protect the analytical zone of the plasma torch from the contamination caused by the gas backflow of surrounding gas was formulated.

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