Phase space analysis of interacting dark energy in f(T) cosmology

In this paper, we examine the interacting dark energy model in f(T) cosmology. We assume dark energy as a perfect fluid and choose a specific cosmologically viable form f(T) = ????T. We show that there is one attractor solution to the dynamical equation of f(T) Friedmann equations. Further we investigate the stability in phase space for a general f(T) model with two interacting fluids. By studying the local stability near the critical points, we show that the critical points lie on the sheet u* = (c ? 1)v* in the phase space, spanned by coordinates (u, v, ??, T). From this critical sheet, we conclude that the coupling between the dark energy and matter c ?? (?2, 0).     

Electrooxidation of iodide in the presence of 4-hydroxycoumarin: application to a simple coulometric titration of 4-hydroxycoumarin.

The electrochemical oxidation of iodide ion in the presence of 4-hydroxycoumarin (1) was studied using cyclic voltammetry and controlled-potential coulometry. The result indicates that the resulting iodine takes part in a halogenation reaction and reacts with 4-hydroxycoumarin (1). According to the obtained results, a new and simple coulometric titration method with potentiometric end-point detection for the determination of 4-hydroxycoumarin (1) is presented. In the presented method, 2-200 micromol of 4-hydroxycoumarin (1) was successfully determined.     

Module Arens regularity for semigroup algebras

We extend the concept of Arens regularity of a Banach algebra to the case that there is an -module structure on , and show that when S is an inverse semigroup with totally ordered subsemigroup E of idempotents, then A=ℓ ¹(S) is module Arens regular if and only if an appropriate group homomorphic image of S is finite. When S is a discrete group, this is just Young’s theorem which asserts that ℓ ¹(S) is Arens regular if and only if S is finite. An erratum to this article can be found at     

Phase Doppler measurements of spray impact onto rigid walls

In this work, an experimental study of spray impact onto a horizontal flat and rigid surface is presented. The phase Doppler technique has been used to characterize both the impacting and the secondary spray in terms of mass and number flux, size distribution and velocities of the droplets above the target. A high-resolution CCD camera has been used to measure the average liquid film thickness formed due to spray impact, whereas a high-speed CMOS camera has been used to characterize the splashing droplets from the wall. This visualization of the splashing phenomenon and the knowledge about the liquid film thickness are used to formulate a new physical model of the crown evolution. Furthermore, information about the incident-to-ejected mass fraction and number fraction are novel contributions of this study. Considerable data are provided comparing the impact of single drops onto a liquid film to impact of drops in a spray, and the significance of the observed differences for modelling efforts is discussed. The measurements of this study are also shown to be rather sensitive to the placement of the phase Doppler measurement volume above the surface and to the operating parameters of the instrument. These effects have been documented and discussed for this particular measurement situation.     

Spray impact onto flat and rigid walls: Empirical characterization and modelling

An experimental study of spray impact onto horizontal flat and rigid surfaces is presented and used as input data for a new empirical model. A phase Doppler instrument has been used to measure drop size and two components of velocity directly above the target. The average film thickness formed due to spray impact has been measured using a high-speed CCD camera. The spray–wall interaction has been characterized in terms of correlations for the velocity and trajectory of secondary droplets and the mass and number ratio of the secondary spray. The novel aspect of the model is that the correlations are based on mean statistics over many events and not on the outcome of single drop impact experiments. Furthermore a rather large range of oblique impact angles have been studied and incorporated into the empirical models as an influencing factor.     

Numerical study on the effects of geometrical parameters and Reynolds number on the heat transfer behavior of carboxy-methyl cellulose/CuO non-Newtonian nanofluid inside a rectangular microchannel

Journal of Thermal Analysis and Calorimetry - Present work studies the effects of microchannel height and Reynolds number on the temperature distribution behavior, pressure drop, and Nusselt number...