Study on phase stabilization and electrical performance of BICO0.20−xNIxVOX solid electrolyte

BICO_0.20?xNI_xVOX solid electrolyte in the composition range 0 ≤ x ≤ 0.20 was synthesized by standard solid-state reactions. The influence of Ni substitution for Co on the relationship between the phase stabilization and electrical performance was investigated by means of X-ray powder diffraction (XRPD), differential thermal analysis (DTA) and AC impedance spectroscopy. The highly conductive γ′-phase was effectively stabilized at room temperature for compositions with x ≥ 0.13 whose thermal stability increases with Ni content. On the other hand, complex plane plots of impedance suggested a major contribution of polycrystalline grain interiors to the overall electrical conductivity and the fastest oxygen-vacancy diffusion in the perovskite vanadate layers at x = 0.13. The dielectric permittivity measurements revealed the fact that suppression of the ferroelectric transition is compositionally dependent. However, a maximum ionic conductivity at lower temperatures (～2.56 × 10^?4 S cm^?1 at 300 °C) was observed for the composition with x = 0.13.     

Study of phase transition of TiO<Subscript>2</Subscript>–CaO system

Electrical conductivity of TiO₂ doped with CaO has been measured at different temperatures for various molar ratios. The conductivity after initially remaining constant till about 140 °C increases with temperature due to the migration of vacancies created by doping. After attaining a maximum value at 240 °C, conductivity decreases due to the collapse of fluorite framework. A second rise in conductivity at high temperature beyond 400 °C indicates the phase transition of TiO₂, from anatase to rutile, which is confirmed by the differential scanning calorimetry results. X-ray powder diffraction, impedance measurements, and Fourier transform infrared spectral studies were also carried out for confirming the doping effect and phase transitions in TiO₂. Doping of TiO₂ with CaO shifts the transition to lower temperatures.     

Hot electron temperature and coupling efficiency scaling with prepulse for cone-guided fast ignition

The effect of increasing prepulse energy levels on the energy spectrum and coupling into forward-going electrons is evaluated in a cone-guided fast-ignition relevant geometry using cone-wire targets irradiated with a high intensity (10(20) W/cm(2)) laser pulse. Hot electron temperature and flux are inferred from Kα images and yields using hybrid particle-in-cell simulations. A two-temperature distribution of hot electrons was required to fit the full profile, with the ratio of energy in a higher energy (MeV) component increasing with a larger prepulse. As prepulse energies were increased from 8 mJ to 1 J, overall coupling from laser to all hot electrons entering the wire was found to fall from 8.4% to 2.5% while coupling into only the 1-3 MeV electrons dropped from 0.57% to 0.03%.     

Random solution of random multivalued operator inclusions

Sufficient conditions for a random solution of random operator inclusions involving random multivalued operators satisfying a general contractive condition are obtained. A simultaneous random solution of the system of two random operator inclusions is also derived.     

Milligram determination of cysteine,cystine and methionine using ammonium hexanitratocerate(IV) as the oxidant

Summary An accurate method has been described for the determination of cysteine, cystine and methionine at the mg level with the use of ammonium hexanitratocerate(IV) as the oxidant. The sample is reacted with an excess of Ce(IV) solution at room temperature (25°) for about 30 min; the unreacted Ce(IV) reagent is then determined by titrating against Fe(II) using ferroin indicator. The precision and accuracy are within ±0.5%.

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Zusammenfassung Eine genaue Methode zur Bestimmung von Milligrammengen Cystein, Cystin bzw. Methionin mit Ammoniumhexanitratocerat(IV) als Oxydationsmittel wurde beschrieben. Man läßt die Probe mit überschüssiger Ce(IV)-Lösung bei Zimmertemperatur reagieren und bestimmt nach ungefähr 30 min den Überschuß durch Titration mit Fe(II) gegen Ferroin als Indikator. Die Genauigkeit liegt innerhalb ±0,5%.

     

Studies on membrane concentration potentials across heavy metal soap discs

The electrostatic effect of specifically adsorbed electroinactive ions upon electrode processes involving adsorbed reactants with a time of adsorption greater than the characteristic time of surface-diffusion jumps is considered. The validity of the most general form of the Frumkin correction term for double-layer effects, with ψ₁ equal to the local potential ₃ at the position occupied by the reactant in the transition state, is first examined on the basis of current molecular theories of electrode kinetics. Subsequently, approximate expressions of ₃ are derived for the case in which adsorbed reactant and adsorbed supporting ion are charged both of equal and of opposite sign. In both cases the logarithm Φ of the rate constant for the electrode reaction at constant applied potential, as corrected for diffuse-layer effects only, is expected to vary linearly with the charge density q_i due to the adsorbed supporting ion. |ΔΦ/Δq_i| is, however, much greater in the case of electrostatic attraction between reactant and adsorbed supporting ion than in the case of electrostatic repulsion. The influence of reactant adsorption with partial charge transfer upon the magnitude of ΔΦ/Δq_i is considered.     

Studies of inorganic precipitate membrane. Part XXX. Membrane selectivity from electrical potential and conductivity measurements

Bi-ionic and multi-ionic potentials across parchment-supported mercuric sulfide membrane with various combinations of 1:1 electrlytes at different concentrations were measured. Membrane conductivity in contact with a single electrolyte was experimentally determined to evaluate selectivity of the membrane with the predetermined values of intramembrane mobility ratio. The selectivity sequence of the membrane was K⁺>Na⁺>Li⁺, which on the basis of the Eisenman–Sherry model of membrane selectivity, points toward the weak field strength of the charge groups attached to the membrane matrix. The permeability ratio of ions within the membrane was also evaluated by use of the equation based on the macroscopic linear laws of nonequilibrium thermodynamics derived by Sandblom and Eisenman. Three different methods of various integrated forms of the Nernst-Plank flux equation were used to derive the potentiometric selectivity constant K_ij^pot of the membrane. These values were close to one another.     

Random fixed points of asymptotically nonexpansive random operators on unbounded domains

The aim of this paper is to prove some random fixed point theorems for asymptotically nonexpansive random operator defined on an unbounded closed and starshaped subset of a Banach space.      

Ultrahigh-intensity laser-produced plasmas as a compact heavy ioninjection source

The possibility of using high-intensity laser-produced plasmas as a source of energetic ions for heavy ion accelerators is addressed. Experiments have shown that neon ions greater than 6 MeV can be produced from gas jet plasmas, and well-collimated proton beams greater than 20 MeV have been produced from high intensity laser solid interactions. The proton beams from the back of thin targets appear to be more collimated and reproducible than are high-energy ions generated in the ablated plasma at the front of the target and may be more suitable for ion injection applications. Lead ions have been produced at energies up to 430 MeV