1,346 research outputs found

    CRYSTALLIZATION KINETICS OF POLYMERIC NANOCOMPOSITES BASED ON POLYAMIDE 12 MODIFIED BY Cr2O3 NANOPARTICLES

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    In situ polymerization method is used for obtaining polymeric composites based on polyamide12 matrix (PA 12), filled with Cr2O3 nanoparticles. The carried out researches result in synthesis method development for polymeric nanocomposites based on PA 12 matrix filled with nano-sized Cr2O3magnetic particles providing uniform embedding of the filler into polymeric matrix without formation of nanoparticles agglomerates. Mechanical tests on samples compression are carried out. It is shown that mechanical properties of polymeric composites (Young’s modulus, durability limit) are decreased for 20-30 % as compared with not modified PA 12 synthesized by means of the chosen method. The influence of the filler on crystallization morphology and kinetics of polymeric nanocomposites is determined by electron microscopy and differential scanning calorimetry. The values of crystallization degree, crystallization rate constant for different supercooling intervals and parameters of Avrami equation are obtained. The initial nucleation is shown to be going on according to non-thermal mechanism, and nanoparticles are not the germs of crystallization. It is stated that nanoparticles are embedded into polymeric matrix and uniformly allocated in crystallites. Research results can find their application at creation of electric and magnetic fields, micro-sized mechanical devices, and at development of new materials for 3D printers

    Technological progress in operation of multiservice sport centers viewed as management issue

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    Objective of the study was to consider benefits of social technologies in application to the modern multiservice sport center (MSC) management systems. To analyze the factors and conditions of effect on the MSC service progress, we performed a questionnaire survey of the MSC clientele and service personnel in July-October 2015 in the Belgorod regio

    Preliminary results on growing second generation biofuel crop miscanthus X Giganteus at the polluted military site in Ukraine

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    Citation: Pidlisnyuk, V., Trögl, J., Stefanovska, T., Shapoval, P., & Erickson, L. (2016). Preliminary results on growing second generation biofuel crop miscanthus X Giganteus at the polluted military site in Ukraine. Nova Biotechnologica et Chimica, 15(1), 77-84. doi:10.1515/nbec-2016-0008The semi-field research on using second-generation biofuel crop Miscanthus x giganteus for restoration of former military site in Kamenetz-Podilsky, Ukraine was carried out during two vegetation seasons. Despite high metal pollution of soil, in particular, by Fe, Mn, Ti, and Zr, no growth inhibition was observed. The concentrations followed pattern soil > roots > stems > leaves. Accumulation of particular metals in roots was different: Fe, Mn and Ti were accumulated rather palpably after the first vegetation season and less tangible after the second one. Cu, Pb and Zn were less accumulative in both vegetation seasons, and for As and Pb the accumulative concentrations were very small. Accumulations in the aboveground parts of the plant in comparison to roots were significantly lower in case of Fe, Ti, Mn, Cu, Zn, Sr and even statistically comparable to zero in case of As, Pb and Zr. Calculated translocation ratio of metals in the plant's parts preferably indicated lack of metals' hyper accumulation. Generally, no correlations were observed between concentrations of metals in the soil and in the upper plant's parts. The research confirmed the ability of Miscanthus x giganteus to grow on the military soils predominantly contaminated by metals. © by Josef Trögl 2016

    Vortex phases in mesoscopic cylinders with suppressed surface superconductivity

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    Vortex structures in mesoscopic cylinder placed in external magnetic field are studied under the general de Gennes boundary condition for the order parameter corresponding to the suppression of surface superconductivity. The Ginzburg-Landau equations are solved based on trial functions for the order parameter for vortex-free, single-vortex, multivortex, and giant vortex phases. The equilibrium vortex diagrams in the plane of external field and cylinder radius and magnetization curves are calculated at different values of de Gennes "extrapolation length" characterizing the boundary condition for the order parameter. The comparison of the obtained variational results with some available exact solutions shows good accuracy of our approach.Comment: RevTex, 11 pages, 10 figure

    The problems of economic accounting components disunity in Russian companies in the economy digitalisation

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    The problematic of the study is determined by the business accounting components disunity in Russian companies revealed as the result of authors’ consulting practice. The purpose of the article was to substantiate the interrelation of accounting components (accounting, tax, management and statistical types of accounting) and to define the lines of research needed for the formation of uniformity and comparability of data. It is also necessary to implement the tasks of digitalisation in economy and to generate information for internal and external interested users. Based on the analysis of legislation on accounting, taxation, management accounting and state statistical observation, the absence in concept of the statistical information for organisations and the current system of statistical accounting in organisations has been established. Detected gap, in the absence of internal and external control, leads to a loss of statistical reporting reliability. It not only determined the relevance of the study, but it creates a precedent for discussion about the advisability of creating in an organisation a separate set of statistical information from accounting, designed to fill in and control reports of federal statistical observation

    The Rotating Gliding Discharge in Quartz Tube and Open Half-Space at Atmospheric Pressure

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    Rotating sliding discharge (RGD) was investigated into limited volume and open half-space. The cur-rent-voltage characteristics of the discharge and its specifications are described. The results of optical research: photos and emission spectra of the discharge are presented

    Light-emitting diode with top electrode as a laminar diffraction grating

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    Symmetry and disorder of the vitreous vortex lattice in an overdoped BaFe_{2-x}Co_xAs_2 superconductor: Indication for strong single-vortex pinning

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    The disordered flux line lattice in single crystals of the slightly overdoped aFe_{2-x}Co_xAs_2 (x = 0.19, Tc = 23 K) superconductor is studied by magnetization measurements, small-angle neutron scattering (SANS), and magnetic force microscopy (MFM). In the whole range of magnetic fields up to 9 T, vortex pinning precludes the formation of an ordered Abrikosov lattice. Instead, a vitreous vortex phase (vortex glass) with a short-range hexagonal order is observed. Statistical processing of MFM datasets lets us directly measure its radial and angular distribution functions and extract the radial correlation length \zeta. In contrast to predictions of the collective pinning model, no increase in the correlated volume with the applied field is observed. Instead, we find that \zeta decreases as 1.3*R1 ~ H^(-1/2) over four decades of the applied magnetic field, where R1 is the radius of the first coordination shell of the vortex lattice. Such universal scaling of \zeta implies that the vortex pinning in iron arsenides remains strong even in the absence of static magnetism. This result is consistent with all the real- and reciprocal-space vortex-lattice measurements in overdoped as-grown aFe_{2-x}Co_xAs_2 published to date and is thus sample-independent. The failure of the collective pinning model suggests that the vortices remain in the single-vortex pinning limit even in high magnetic fields up to 9 T.Comment: 11 pages, 6 figure
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