Dust ion‐acoustic solitons collision in weakly relativistic plasmas with superthermality‐distributed electrons and positrons: Higher‐order phase shifts

The higher‐order (H‐O) phase shift of dust ion‐acoustic solitons (DIASs) in a weakly relativistic plasma is examined considering the influence of both superthermality‐distributed electrons and positrons. Employing the extended Poincaré–Lighthill–Kuo method (EPLKM), the Korteweg–de Vries equations (KdVEs) and the deviation in trajectories of DIASs (i.e., phase shifts) are obtained after the collision. For obtaining H‐O phase shifts of DIASs, the fifth‐order dispersion terms are added into KdVEs. The effects of the relativistic factor for a weakly relativistic regime and the superthermality of both electrons and positrons on the H‐O phase shifts are discussed. Numerical analysis gives rise to important highlights on the excitation and the collision of DIASs in astrophysical situations such as a pulsar magnetosphere.     

Oxidation of Methyl Propanoate by the OH Radical

Russian Journal of Physical Chemistry A - Atmospheric oxidation of methyl propanoate (MP) by the OH radical has been performed using density functional theory (BMK, BBIK) and ab initio (MP2,...     

PHASE TRANSITIONS IN COLLOIDAL SYSTEMS PART I: REFRACTOMETRIC STUDY OF THE BINARY SYSTEM SDS+WATER OR PENTANOL-1+WATER AND THE TERNARY SYSTEM WATER+SDS+PENTANOL-1 AT 298.15 K.

The monophasic ranges for the binary systems water+SDS and water+pentanoM and for the ternary system water+SDS+pentanoM has been studied by means of refractametric experiments at 298 K.

The curves of refractometric index versus the composition of the system, has shown the existence of several transitions labeled successive critic micellar concentrations. These transitions are detected by a change of the variation of the refractive index.

We have evidenced the very importance of the pentanol-1 in these amphiphilic solutions, acting as a surfactant or as an oil according the concentration.

For these systems it is passible to better understand the phase inversion phenomena.

At last, we present the phase diagram indicating the concentration range of the different microstructures.     

Spectroscopic and voltammetric studies of Pefloxacin bound to calf thymus double-stranded DNA

Spectral and electrochemical studies have been carried out on the interaction of pefloxacin with calf thymus double-stranded dsDNA. The voltammetric behavior of pefloxacin was investigated at glassy carbon, carbon paste and dsDNA-modified carbon paste electrodes using cyclic voltammetry. Pefloxacin was oxidized, yielding one irreversible oxidation peak. The modification of the carbon paste surface with dsDNA allowed an accumulation process to take place for pefloxacin such that higher sensitivity was achieved compared with the bare surface. The response was characterized with respect to ionic strength, accumulation time, pefloxacin concentration, and other variables. The stripping differential pulse voltammetric response showed a linear calibration curve in the range 1.0×10^–7–1.0×10^–5 mol l^–1 with a detection limit of 5.0×10^–8 mol l^–1 at the dsDNA modified electrode. The method was applied to the direct determination of pefloxacin in diluted urine samples.     

Ring-closing double reductive amination route to aza-heteroannulated sugars

1,4-Dicarbonyl derivatives of glycosides are produced by ozonolysis or Wacker oxidation. A stable ozonide is isolated and a carbonyl group reduced whilst maintaining the ozonide functionality. The 1,4-dicarbonyl compounds are converted to various N-substituted pyrrolidines by diastereoselective double reductive amination The resulting aza-heteroannulated sugars no significant inhibition of any glycosidase, with the exception of compound 12g, which is a weak inhibitor of β-galactosidase.     

Grafted polymer membranes with extractive agents for the extraction process of VO2+ ions

To conduct experiments related to the facilitated extraction phenomenon and recovery of vanadium ions VO₂⁺, two grafted polymer membranes were prepared; containing respectively cholic acid and azithromycin as extractive agents and the obtained membranes were characterized. All experiments for the facilitated extraction phenomenon of these ions were carried out. Kinetic and thermodynamic models, based on the interaction of the substrate S (VO₂⁺) with the extractive agent T, and the diffusion of the formed entity (TS) through the membrane were developed, to determine the macroscopic parameters, permeability P and initial fluxes J₀, and the microscopic parameters, association constants K_ass and apparent diffusion coefficients D*, related to the formation of entities TS and their diffusion. A clear evolution of these parameters, depending on various factors (substrate concentration C₀, extractive agent concentration and feed and receiving phases temperature), and high permeabilities for this extraction phenomenon of VO₂⁺ ions were observed for this membrane type. Copyright © 2016 John Wiley & Sons, Ltd.     

A class of generalized Ornstein transformations with the weak mixing property

It is shown that there is a class of Ornstein transformations, distinct from the Ornstein mixing class, which are almost surely weak mixing     

Existence of Renormalized Solutions for Nonlinear Parabolic Equations

We give an existence result of a renormalized solution for a class of nonlin- ear parabolic equations b（x,u）/ t-div （a（x,t,u, u））＋g（x,t,u,u ）＋H（x,t, u）=f,in QT, where the right side belongs to LP＇ （0,T;W-1,p＇（Ω）） and where b（x,u） is unbounded function of u and where - div （ a （ x, t, u, u） ） is a Leray-Lions type operator with growth ｜u ｜p- 1 in V u. The critical growth condition on g is with respect to u and no growth condition with re sp ect to u, while the function H （x, t, u） grows as｜ u ｜p - 1.