Simulation of thin disk laser pumping process for temperature dependent Yb:YAG property

A novel model of Cw diode pumped Yb:YAG thin disk laser has been presented to simulate absorption pump power distribution by Monte-Carlo ray tracing. Comparing obtained results with the common distribution function indicate the offered model is quite trustful. So these findings help to evaluate temperature distribution due to the 3D finite element analyses (FEA) based on heat conduction equation. To improve our simulation the temperature dependent of crystal property such as the absorption coefficient, thermal conductivity, stimulated emission cross section and Boltzman population factors are considered by a numerical iterative approach.     

InCl3 as an efficient catalyst for synthesis of oxazolines under thermal, ultrasonic and microwave irradiations

Efficient synthesis of 2-oxazolines by the reaction of nitriles with β-aminoalcohols using InCl₃ as catalyst under reflux conditions is reported. This catalyst can be successfully applied to the chemoselective conversion of dicyanobenzenes to their corresponding mono- and bis-oxazolines. The application of ultrasonic and microwave irradiation improved the yields and reduced the reaction times. Another advantage of this catalytic system is its ability to carry out large-scale reactions under ultrasonic and MW irradiations. Alkylnitriles such as acetonitrile was also converted to its corresponding 2-methyloxazoline in the presence of catalytic amounts of InCl₃.     

The effect of oxidation temperature on the nano crystalline structure of ZrO2 films deposited on silicon and glass substrates

Zirconium oxide (ZrO₂) films have been prepared by using ex situ thermal oxidation of sputtered Zr films on glass and silicon substrates. XRD patterns show that a highly monoclinic (111) preferential orientation of ZrO₂ phase can be formed with increasing the oxidation temperature. According to XRD patterns in all thermal oxidized samples silicon oxide phase is present as interfacial layer at the Zr (ZrO₂) / Si (glass) interface. In the case of silicon substrates, crystallite sizes obtained from ZrO₂ peak with higher intensity reveal an increase with substrate temperature. AFM measurement shows on the whole a decrease of average surface roughness with oxidation temperature. The electrical property of the prepared films is investigated by means of four point probe measurement. An abrupt increase of sheet resistivity occurs when the crystallinity of ZrO₂ phase enhances at higher temperature. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

An improved electrochemical method for the synthesis of some benzofuran derivatives

Electrochemical oxidation of catechol and some 3-substituted catechols (1a--c) has been studied in the presence of 2-chloro-5,5-dimethyl-1,3-cyclohexanedione (3) in aqueous solution using cyclic voltammetry and controlled-potential coulometry. The results indicate that the quinones derived from catechols (1a--c) participate in a Michael addition reaction with 2-chloro-5,5-dimethyl-1,3-cyclohexanedione (3) with consumption of only two electrons per molecule of (1a--c) to from the corresponding benzoforans (10a--c). The electrochemical synthesis of benzofurans has been successfully performed at a carbon rod electrode and in an undivided cell with high yields and purity.     

Exact Solutions of Five Complex Nonlinear Schrödinger Equations by Semi-Inverse Variational Principle

In this paper, we establish exact solutions for five complex nonlinear Schrödinger equations. The semi-inverse variational principle (SVP) is used to construct exact soliton solutions of five complex nonlinear Schrödinger equations. Many new families of exact soliton solutions of five complex nonlinear Schrödinger equations are successfully obtained.     

Density-Dependent Conformable Space-time Fractional Diffusion-Reaction Equation and Its Exact Solutions

In this article, a special type of fractional differential equations(FDEs) named the density-dependent conformable fractional diffusion-reaction(DDCFDR) equation is studied. Aforementioned equation has a significant role in the modelling of some phenomena arising in the applied science. The well-organized methods, including the exp(-φ(ε))-expansion and modified Kudryashov methods are exerted to generate the exact solutions of this equation such that some of the solutions are new and have been reported for the first time. Results illustrate that both methods have a great performance in handling the DDCFDR equation.     

Optical solitons for a family of nonlinear ($$$$)-dimensional time-space fractional Schrödinger models

In this paper, the sine–cosine method is employed to construct exact solutions of the space-time fractional (\(1+1\))-dimensional nonlinear Schrödinger models. Many new families of exact traveling wave solutions of these models are successfully obtained. It is shown that the proposed method provides a more powerful mathematical tool for solving nonlinear space-time fractional evolution equations in mathematical physics.