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  • Influence of the dielectric properties of the medium on the optical properties of enclosed gold nanoparticles

    In this paper, samples containing gold nanoparticles (NPs) distributed in different optically transparent media have been synthesized and characterized. A liquid (aqueous) and a solid (porous silicate glass and polymer (polyvinylpyrrolidone)) media were used. The samples obtained were characterized by optical spectroscopy and electron microscopy. The position of plasmon resonance band was analyzed depending on the dielectric constant of the medium.

    Keywords: gold nanoparticles, colloidal solution, polymer, porous glass

  • Determination of sound velocity in sediments under environmental monitoring

    The bulk of the pollutants accumulate in marine sediments. Hence the importance of the problem of the continuous monitoring of the state of the bottom and the bottom of sedimentary structures of inland waters and seas. The paper presents a method of remote sensing bottom soil to determine the speed of sound in the bottom ground. The proposed method allows to carry out measurements at the joint location of the emitter and receiver. The proposed method is a method of beam parameter. For measurements by the method of beam parameter must either have extended the receiving antenna system capable to determine the direction of arrival of the reflected acoustic signals from the bottom with a simple omnidirectional radiator or emit highly directional sound source and relatively easy to take an extended receiving antenna. Using parametric array can be formed acoustic beam width several degrees. This beam width is sufficient to implement the method of beam parameter. The authors have proposed an approximate method of beam parameter allows you to combine the location of the transmitter and the receiver, thus greatly simplifying the receiving antenna. To test the adequacy of the method was carried out modeling and experimental studies. In the simulation, the real parameters laid marine bottom of the layered structure and foster and radiating systems. As a result of the simulation were defined the limits of applicability of the proposed method in the study of marine soils. To determine the velocity of sound in the sea bed sediments with acceptable accuracy must emit acoustic signals at an angle less than 10 degrees. Experimental studies in acoustic basin showed qualitative agreement with the theoretical findings.

    Keywords: remote sensing acoustic, classification of marine sediments, parametric profiler

  • Local atomic and electronic structure features of copper ion Cu2 + in aqueous solutions

    The study of copper ion (Cu2+) environment in aqueous solution was performed by means of X-ray absorption spectroscopy. X-ray absorption spectra for various concentrations of aqueous solutions of CuCl2 were measured. The testing of near-edge fine structure approach for calculating X-ray absorption Cu K-edge spectra of copper ion (Cu2 +) coordinated complex by finite difference method for solution of Schrödinger equation were held . A model of local environment of copper ion (Cu2 +) in aqueous solutions is proposed.

    Keywords: X-ray absorption spectroscopy, 3d-metals ions, aqueous solutions, local environment, finite difference method, coordination complexes

  • The dependence of the local environment of copper and cobalt ions in aqueous solutions, depending on the acidity of the solution

    A study of X-ray absorption spectra depending solution of copper (II) and cobalt from the time of preparation of these solutions (immediately prior to the measurement and aged for six months), as well as the dependence of the spectra on the acidity of the solution (different levels of pH 5.7 and 1, which is achieved by addition of hydrochloric acid). Processing of the experimental spectra were in the software package Athena. The study established according to the experimental X-ray absorption spectra of the solution of copper (II) and cobalt chloride on the test conditions.

    Keywords: X-ray absorption spectroscopy, soft X-rays, copper chloride, copper (II), cobalt chloride aqueous solution, X-ray absorption spectrometer Rigaku R-XAS, a cell with kapton window

  • Spraying of nonisocyanate insulation foams

    This article describes a method for producing two-component nonisocyanate insulating foams and technology of its spraying on the insulated surface. It describes the device, which, along with standard equipment, includes principally new design of components pre-mixing chamber. Constructive solutions described in the article will allow using the compositions which have different time and temperature of curing than conventional PU foams.

    Keywords: Keywords: spray foams, insulating foams, nonisocyanate urethanes, pre-mixing chamber.

  • Special features of mechanochemical activation Al-Si mixture and the formation of hot-deformed powder material based on the mixture

    This paper presented the study of the mechanochemical activation powder mix in dry and liquid grinding media, accompanied by agglomeration of the particles. It Is shown that when agglomerate particles having a bimodal size distribution is forming during the treatment in a dry grinding media and partially (2 wt % ) decaying at grinding by pestle in mortar. The transition to liquid grinding media is leading to a unimodal size distribution and increasing dispersion of the agglomerated particles, characterized by secondary agglomerating when using the alcohol and destruction when using activation in saturated aqueous solution of boric acid. Inherited effect mechanical activation parameters on the compaction process during cold compaction and hot stamping has been determined. Application treated in a high energy mill in an grinding media saturated aqueous H3BO3 Al-Si powder mix results in the formation of moldings with low cold-pressing relative density (0.735) and the activation of the hot stamping compaction (|εh| = 0,592) providing production of hot-deformed powder material with increased mechanical properties.

    Keywords: mechanochemical activation, hot-deformed powder material, aluminum, silicon, dispersion, agglomeration

  • Ultrasonic examination technology of nuclear reactor’s industrial pipelines

    Acoustic system parameters were selected and calculated: wave modes used when controlling, wave entry and frequency angles according to kind of decay process and ultrasonic attenuation. Control procedure was developed

    Keywords: ultrozvuk, frequency, attenuation process, technology, acoustic system

  • The experimental research the passage of the ultrasonic beam through charging the layered structure

    This paper shows the results of the experimental research the passage of the ultrasonic beam through modifiable layered structure in order to obtain data on changes in levels of pressure in the front slice of the acoustic field. This paper presents the spatial distribution characteristics of the acoustic field after passing the various layers in the liquid. Celebrated not only offset the propagation path, but also change the chart pressure in the front slice on the amplitude level , the width of the chart, the position of the lateral lobe and its amplitude.

    Keywords: Ultrasound, layered medium, experimental assembly, refraction.

  • Synthesis and electrochemical properties of LiMn1/3Cr1/3Fe1/3O2 solid solution with the structure of α-NaFeO2

    The solid solution of  LiMn1/3Cr1/3Fe1/3O2 with the structure of α-NaFeO2  isostructural with the widely used LiCoO2  has been synthesized and investigated as a cathode material. Rated voltage of LiMn1/3Cr1/3Fe1/3O2  relative to the lithium is 4 V.  The possibility of charging − discharging the material to a specific capacity of 220-250 mAh/g at currents of C/15-C/50 without phase transformations has been experimentally demonstrated. 

    Keywords: lithium-ion batteries, cathode materials, Delafosse, solid solution, X-ray structural analysis, electrochemical properties

  • Local Atomic and Electronic Structure of the Fe dopants in AlN:Fe Nanorods

    Fe-doped AlN nanorods were studied by means of x-ray absorption spectroscopy above the Fe K- and L2,3- edges. Theoretical simulations of the x-ray absorption spectra show that Fe atoms mainly substitute Al. A minor fraction of Fe interstitials or Fe-Al-N ternary alloy can be identified as well. Bader’s AIM analysis predicts that neutral substitutional FeAl defect is in 2+ charge state, though Al in pure AlN is in 3+ charge state.  Fe L2,3 absorption spectra and photoluminescence data indicate the coexistence of Fe2+/Fe3+ in AlN:Fe nanorods so different charge states of substitutional FeAl should co-exist.

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

  • Local atomic and electronic structure of nanostructured condensed materials for rechargeable current sources on the basis of V2O5/Fe/LiF nanocomposite within charge-discharge cycle

    In this paper we study of the local atomic and electronic structure of nanostructured condensed material for rechargeable current sources on the basis of 15mas.%V2O5/Fe/LiF nanocomposite within charge-discharge cycle. Principle component analysis (PCA) of the series of Fe K-edge spectra collected during 1 st charge showing the concentrations of the components Fe, FeF2 and V[FeV]O4. We found the changes in the V oxidation state from the analysis of the experimental Fe K- and V K- XANES spectra. Total and partial density of states of components are presented.

    Keywords: nanostructured materials for rechargeable current sources, dynamics of local atomic and electronic structures, XANES, DFT

  • Channeling of X-ray fluorescence excited in hollow microcapillaries.

    The possibility of channeling X-ray fluorescence inside the hollow microvascular at the energy of the exciting radiation in the vicinity SiL2, 3 - absorption edge has been researched. Theoretically obtained the angular distribution of the field passing through the microchannels. The calculation model of inhomogeneous waveguide layer with the generation of X-ray fluorescence inside the walls of the microchannels shows the possibility of escape of radiation at large angles.

    Keywords: channeling of X-ray fluorescence, microchannel plates, focusing of X-ray radiation

  • Development of elements for "smart clothes" based on the electrochemical charge storage system for microsystems technique

    In this paper we propose basic geometric, mass and electrical parameters of the element for collection of static electricity from the surface of the textile. This element is a reversible electrochemical charge storage system based on nanostructured nickel oxide and carbon cloth. Element has a planar structure, it is flexible, lightweight, safety and ergonomic. Proposed element can be used as a power source for the Microsystems technique in "smart clothes".

    Keywords: "smart clothes", microsystems technique, static electricity, supercapacitor, composite material NiO/C

  • Gold nanoparticles functionalisation by long-chain thiol and amine ligands: study of local atomic and electronic structure of ligand-gold bond

    In the present work we report on the study of local atomic and electronic structure of gold nanoparticles funnctionalised by thiol and amine containing long-chain ligands. The study of nanoscale atomic structure is performed by means of X-ray absorption spectroscopy (XANES: X-ray Absorption Near-Edge Structure) and computer simulation. In consequence of the experimantally obtained data analysis and computer simulation it was obtained that strong bonding takes place when 11-mercaptoundecanoic acid is bound to the gold nanoparticles surface, forming a chemical bond Au-S 0.25 nm in length. Weaker bonding is observed when forming bond between dodecylamine and gold nanoparticles surface atom resulting in Au-N bond 0.23 nm in length. Supplementary XANES spectra analysis by means of density functional theory reveals the nature of formation of the investigated nanoscale structure.

    Keywords: nanoscale structure of matter, X-ray absorption spectroscopy, XANES, density functional theory, nanoparticles functionalisation

  • 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