Synthesis of Pyrimidinone and 5‐unsubstituted 4, 6‐diarylpyrimidine‐2(1H)‐ones by Using Nano Magnetic Catalyst under Solvent Free Condition

Nano magnetic‐supported sulfonic acid is found to be a powerful and reusable heterogeneous catalyst for the efficient synthesis of pyrimidinones. In this study we use various ketones such as acetophenone and cyclopentanone instead of β‐keto ester in one‐pot synthesis of pyrimidinone at biginelli like reaction. Our objective is to improve conditions for the synthesis of multicomponent reactions using nano magnetic catalyst under solvent free condition. A number of excellent and significant results have been developed that lead our perspective understanding the effect of the magnetic nanoparticles when they are used as catalysts.     

Organic Electrosynthesis as a New Facile and Green Method for One‐pot Synthesis of Nanosized Particles of Octahydro‐imidazo[1,2‐a]quinolin‐6‐one Derivatives via a Multicomponent Reaction

Organic electrosynthesis as a new facile and green method was applied for one‐pot synthesis of octahydro‐imidazo[1,2‐a]quinolin‐6‐one derivatives, via a three component condensation of a dimedone, an aldehyde and 2‐(nitromethylene)imidazolidine in propanol in an undivided cell in the presence of sodium bromide as an electrolyte at room temperature. In this study, the anion of dimedone that was produced on the cathode reacted with aromatic aldehydes through the Knoevenagel reaction and then the product condensed with 2‐(nitromethylene)imidazolidine that resulted in a highly efficient formation of octahydro‐imidazo[1,2‐a]quinolin‐6‐one with 50–96% substance yields.     

Exact Solutions of Five Complex Nonlinear Schr¨odinger Equations by Semi-Inverse Variational Principle

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

First principles study of electronic properties,interband transitions and electron energy loss of <Emphasis Type="Italic">α</Emphasis>-graphyne

The electronic and optical properties of α-graphyne sheet are investigated by using densityfunctional theory. The results confirm that α-graphyne sheet is a zero-gap semimetal. Theoptical properties of the α-graphyne sheet such as dielectric function,refraction index, electron energy loss function, reflectivity, absorption coefficient andextinction index are calculated for both parallel and perpendicular electric fieldpolarizations. The optical spectra are strongly anisotropic along these two polarizations.For (E ∥x), absorption edge is at 0 eV, while there is noabsorption below 8 eV for (E ∥z).     

Preparation,Characterization and Electrochemical Application of ZnS/ZnAl2S4 Nanocomposite for Voltammetric Determination of Methionine and Tryptophan Using Modified Carbon Paste Electrode

ZnS/ZnAl₂S₄ nanocomposite and 2‐chlorobenzoyl ferrocene, were synthesized and used to construct a modified carbon paste electrode. The electrooxidation of methionine at the surface of the modified electrode was studied. Under the optimized conditions, the square wave voltammetric (SWV) peak current of methionine increased linearly with methionine concentration in the range of 5.0×10^?8 to 8.0×10^?4 M and detection limit of 10.0 nM was obtained for methionine. The prepared modified electrode exhibits a very good resolution between the voltammetric peaks of methionine and tryptophan which makes it suitable for the detection of methionine in the presence of tryptophan in real samples.     

Investigation of polycarbonate/acrylonitrile butadiene styrene/multiwall carbon nanotube nanocomposites under impact loading

In this study, the effect of polycarbonate (PC)/acrylonitrile butadiene styrene (ABS)‐reinforced multiwall carbon nanotube (MWCNT) nanocomposites under a high‐velocity impact was investigated. PC/ABS (70/30 w/w)/MWCNT nanocomposites containing 1, 2, and 4 wt% were used to manufacture samples for this study. The samples were fabricated in sheet form with 100 × 100 mm dimensions and tested by gas gun for high‐velocity impact tests. The experimental results indicate that the energy absorption, limit velocity, and tensile modulus of the nanocomposite samples increased by approximately 121%, 52%, and 103% for the PC/ABS (70/30 w/w)/2 wt% MWCNT samples respectively. These results were confirmed by a transmission electron microscopy analysis test that was conducted for the state of dispersion of MWCNTs in the nanocomposite samples. The transmission electron microscopy results show that the best morphological structure of carbon nanotube at the interface of PC and ABS is that for the nanocomposite containing 2 wt% MWCNTs, which led to improved interface of the nanocomposites and higher mechanical properties. Copyright © 2016 John Wiley & Sons, Ltd.     

Absolute Value Equations with Tensor Product Structure: Unique Solvability and Numerical Solution

Applications of Mathematics - We consider the absolute value equations (AVEs) with a certain tensor product structure. Two aspects of this kind of AVEs are discussed in detail: the solvability and...     

Joint Reliability Function of Coherent Systems with Shared Heterogeneous Components

In this paper, we consider two coherent systems having shared components. We assume that in the two systems there are three different types of components; components of type one that just belong to the first system, components of type two that lie only in the second system and components of type three that are shared by the two systems. We use the concept of joint survival signature to assess the joint reliability function of the two systems. Using this concept, some representations for the joint reliability function of the system lifetimes are obtained under two different scenarios of component failures. In the first scenario, we assume that the components of the systems fail according to different counting processes such as non-homogeneous Poisson processes. In the second scenario, it is assumed that the component lifetimes of each type are exchangeable while the three types of component lifetimes can be independent or dependent. To illustrate the theoretical results, two systems with shared components are studied numerically and graphically.

     

Modified Magnetite Nanoparticles for Hexavalent Chromium Removal from Water

Water treatment is an important concern of human societies. Using magnetic nanoparticles as adsorbents for metal removal has been greatly considered due to their particular characteristics such as small sizes, high surface area to volume ratios, and good magnetic properties. In the present study, a modification was implemented in magnetite particles by functionalized carbon nanotubes and carboxylic groups to enhance the performance of magnetite particles in removing hexavalent chromium from water using the adsorption method. The applicability of the nanoadsorbent and magnetic nanoparticles was compared based on adsorption factors affecting the chromium removal including pH, contact time, pollutant concentration, and the adsorbent amount. Properties of the nanocomposites were analyzed by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The results show that the highest percentage of Cr (VI) removal for both adsorbents was under acidic ambient conditions and lasted less than 45 minutes. The study of Langmuir, Freundlich, and Temkin isotherms in the prediction of adsorption behavior revealed that the Langmuir model better fitted the adsorption equilibrium data. The kinetic analysis of pseudo-first and second-order equations showed that the pseudo-second-order equation was more suitable for describing the kinetic behavior of data. Moreover, the obtained nanocomposite had a better performance in Cr (VI) removal from water in comparison to magnetite nanoparticles.