Ultrasound promoted synthesis of 5-hydroxy-5-trihalomethyl-4,5-dihydroisoxazoles and beta-enamino trihalomethyl ketones in water

A convenient method for the preparation of 5-hydroxy-5-trihalo-4,5-dihydroisoxazoles and beta-enamino trihalomethyl ketones, from the reaction of 1,1,1-trihalo-4-alkoxy-3-alken-2-ones with hydroxylamine and anilines, respectively, using water as solvent and under ultrasound irradiation is reported.     

Efficient synthesis of 6-aryl-4-trifluoromethyl/ethoxycarbonyl-2H-pyran-2-ones through self-condensation of penta-2,4-dienenitriles

An efficient synthesis of two new series of 6-aryl-4-trifluoromethyl-2H-pyran-2-ones and 6-aryl-4-carboxyethyl-2H-pyran-2-ones, obtained through the self-condensation reaction of 5-aryl-5-methoxy-3-(trifluoromethyl)penta-2,4-dienenitriles 3 and ethyl 4-aryl-2-(cyanomethylene)-4-methoxybut-3-enoates 4 respectively, is reported. The self-condensation reaction of the enoates 4 was performed in water in the presence of hydrochloric acid whereas the self-condensation reaction of the penta-2,4-dienenitriles 3 required the use of zinc bromide and hydrochloric acid in order to give the respective 2H-pyran-2-ones. Products were obtained up to 97% yield.     

Efficient synthesis and dehydration reaction of trichloromethylated 2‐(3‐phenyl‐5‐hydroxy‐4,5‐dihydro‐1H‐pyrazol‐1‐yl)‐4‐aryl‐5‐alkylthiazoles

A convenient method for the synthesis of a novel series of 11, specifically substituted, noncondensed 5,5‐bicycles 2‐[3‐phenyl‐5‐hydroxy‐5‐trichloromethyl‐4,5‐dihydro‐1H‐pyrazol‐1‐yl]‐4‐aryl‐5‐alkylthiazoles ( 3a–k ; 65–94% yield) from the reactions of 3‐phenyl‐5‐hydroxy‐5‐trichloromethyl‐4,5‐dihydro‐1H‐1‐pyrazolethiocarboxyamide ( 1 ) with substituted 2‐bromo‐4′‐acetophenones ( 2a–f ) and 2‐bromo‐4′‐propiophenones ( 2g–k ) is reported. Dehydration of compounds 3a–k with a mixture of concentrated sulfuric acid/chloroform furnished the corresponding 2‐[3‐phenyl‐5‐trichloromethyl‐1H‐pyrazol‐1‐yl]‐4‐aryl‐5‐alkylthiazoles ( 4a–k ) in good yields (61–93%). © 2003 Wiley Periodicals, Inc. Heteroatom Chem 14:132–137, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.10113     

Focusing surface plasmons on Er3+ ions through gold planar plasmonic lenses

Gold plasmonic lenses consisting of a planar concentric rings-groove with different periods were milled with a focused gallium ion beam on a gold thin film deposited onto an Er³⁺-doped tellurite glass. The plasmonic lenses were vertically illuminated with an argon ion laser highly focused by means of a 50× objective lens. The focusing mechanism of the plasmonic lenses is explained using a coherent interference model of surface plasmon-polariton (SPP) generation on the circular grating due to the incident field. As a result, phase modulation can be accomplished by the groove gap, similar to a nanoslit array with different widths. This focusing allows a high confinement of SPPs that can excite the Er³⁺ ions of the glass. The Er³⁺ luminescence spectra were measured in the far-field (500?C750?nm wavelength range), where we could verify the excitation yield via the plasmonic lens on the Er³⁺ ions. We analyze the influence of the geometrical parameters on the luminescence spectra. The variation of these parameters results in considerable changes of the luminescence spectra.     

Steering in computational science: Mesoscale modelling and simulation

This paper outlines the benefits of computational steering for high performance computing applications. Lattice-Boltzmann mesoscale fluid simulations of binary and ternary amphiphilic fluids in two and three dimensions are used to illustrate the substantial improvements which computational steering offers in terms of resource efficiency and time to discover new physics. We discuss details of our current steering implementations and describe their future outlook with the advent of computational grids.     

First integrals and analytical solutions of the nonlinear fin problem with temperature-dependent thermal conductivity and heat transfer coefficient

Fin materials can be observed in a variety of engineering applications. They are used to ease the dissipation of heat from a heated wall to the surrounding environment. In this work, we consider a nonlinear fin problem with temperature-dependent thermal conductivity and heat transfer coefficient. The equation(s) under study are highly nonlinear. Both the thermal conductivity and the heat transfer coefficient are given as arbitrary functions of temperature. Firstly, we consider the Lie group analysis for different cases of thermal conductivity and the heat transfer coefficients. These classifications are obtained from the Lie group analysis. Then, the first integrals of the nonlinear straight fin problem are constructed by three methods, namely, Noether’s classical method, partial Noether approach and Ibragimov’s nonlocal conservation method. Some exact analytical solutions are also constructed. The obtained result is also compared with the result obtained by other methods.