7,353 research outputs found

    Determination of Influence of Auxiliary Ingredients on Antioxidant Activity of Extract of Leaves of the Quince and Grapes Seed Meal in Phytogel with the Use of Spectrometric Method with the Dpph Indicator System

    Get PDF
    To study an impact of auxiliary substances on gel containing extracts of quince leaves and grape seed meal, which is based on polymethylsiloxane.Pharmaco - technological and physicochemical methods. In this study, a spectrophotometric method is applied to determine an antioxidant activity of the gel.We examined an impact of auxiliary substances on the gel. According to the results of studies we chose auxiliary ingredients which improve not only gustatory quality but also technological parameters. Applying spectrometric analysis, we investigated an antioxidant activity of phytogel. The gel has a structure of rigid matrix, which is built through a process of condensation of methylsilanetriol and siloxane bonds between the silicon atoms, which makes it possible to maintain and stabilize active natural ingredients. The experiment proved that the extract of leaves of quince and grape seed meal have some antioxidant activity. But, upon the introduction of stevia extract as a coregent taste, the gel that contains quince leaf extract and grape seed meal increases the antioxidant activity. Phytogel has antioxidant activity of 84% relative to the reference sample, which suggests that the gel can resist the harmful effects of free radicals, which are constantly produced in the human organismIt was confirmed that the addition of auxiliary substances into the gel with the extracts of quince leaves and grape seed meal based on polymethylsiloxane increases bioavailability and therapeutic efficiency, in particular, the antioxidant activity, of the gel.Stevia extract as an adjuvant in the phytogel, as gustatory corrector, increases the antioxidant activity of phyto pharmaceutical drugs

    Pairing state in multicomponent superconductors

    Full text link
    We use the microscopic weak coupling theory to predict the pairing state in superconductors of cubic, hexagonal, or tetragonal symmetry, where the order parameter is multicomponent, i.e., transforms according to either a 2-dimensional or a 3-dimensional representation of the crystal point group. We show that the superconducting phase usually breaks the time-reversal symmetry for singlet multicomponent superconductors. The superconducting order parameter for triplet superconductors in most cases turns out to be non-magnetic.Comment: 7 page

    Resonant photoemission spectroscopy of Cu(InGa)Se2 materials for solar cells

    Full text link
    The electron structure of CuIn1 - x Ga x Se 2 single crystals is determined via resonant photoemis-sion and the main regularities of its transformation upon varying concentration x from 0 to 1 are established. The dependence of the shape of valence band spectra on the photon energy is studied. Integral photoemission intensities are shown to be determined by atomic photoionization cross sections. Processes of the direct and two-step creation of photoelectrons accompanying photoemission and the participation of internal states in the spectra of electrons from valence bands are studied. Two-hole final states in photoemission are obtained upon threshold excitation of the Cu 2p level. The strong interaction of holes leads to the multiplet splitting of these states. Partial densities of the components' states are determined using the energy dependence of atomic photoionization cross sections. © 2013 Allerton Press, Inc

    Effects of spin polarization on resonant photoemission from d-f states in TbNi2Mnx compounds

    Full text link
    Resonant photoemission in narrow-band materials is described by the sum of first-and secondorder transitions, their quantum-mechanical interference leads to an increase in the spectrum from the valence bands and the appearance of an asymmetric dependence on the photon energy. These effects are studied theoretically and experimentally using the example of three-component intermetallic compounds TbNi2Mnx. The competition between the elastic and inelastic photoemission channels leads to a different dependence of photoemission spectra from nickel and manganese on photon energy. The elastic channel is realized on atoms with large magnetic moments, the inelastic Auger decay occurs on atoms with small moments. © 2018 The Authors, published by EDP Sciences.The research was carried out within the state assignment of FASO of Russia (theme uQ" ant" No. 01201463332), supported in part by RFBR (No. 18-02-00060) and UD RAS (No.15 -8 2-10). The authors express their gratitude to A. Preobrazhenskii and N. Vinogradov (synchrotron MAX-Lab, Lund, Sweden) for their assistance in carrying out experiments

    On a class of 2D integrable lattice equations

    Full text link
    We develop a new approach to the classification of integrable equations of the form uxy=f(u,ux,uy,zuzˉu,zzˉu), u_{xy}=f(u, u_x, u_y, \triangle_z u \triangle_{\bar z}u, \triangle_{z\bar z}u), where z\triangle_{ z} and zˉ\triangle_{\bar z} are the forward/backward discrete derivatives. The following 2-step classification procedure is proposed: (1) First we require that the dispersionless limit of the equation is integrable, that is, its characteristic variety defines a conformal structure which is Einstein-Weyl on every solution. (2) Secondly, to the candidate equations selected at the previous step we apply the test of Darboux integrability of reductions obtained by imposing suitable cut-off conditions
    corecore