Common fixed points for four maps in cone metric spaces

The existence of coincidence points and common fixed points for four mappings satisfying generalized contractive conditions without exploiting the notion of continuity of any map involved therein, in a cone metric space is proved. These results extend, unify and generalize several well known comparable results in the existing literature.     

Regioselective Synthesis of Para‐Bromo Aromatic Compounds

Reaction of substituted benzene rings with N‐bromophthalimide, under neutral conditions, gave the corresponding bromo derivatives with a preference for the formation of the para bromo isomer over the ortho isomer. The simple work‐up procedure minimizes loss of product and the yields are good.     

The virtual mass of an oblate-ellipsoidal bubble

A semi-analytical solution is presented for the virtual mass coefficient of an oblate-ellipsoidal bubble rising in liquid. The solution was found to be a function of Weber number. The present solution compared well with the numerical solution of the lattice Boltzmann method and the analytical solutions of other investigators.     

Development of temporal spectroscopic properties for Xerogel matrices doped with Rhodamine 6G dye

The solid host of a laser dye modifies its spectroscopic properties with respect to its liquid host. During the Sol-Gel process the dye molecules suffer from changing their environment. Two parameters affect this matter, the change in the concentration due to the evaporation of the solvent (drying) and the caging of dye molecules inside the pores or attachment to the silica network. Rhodamine 6G absorption and fluorescence spectra with different concentrations, during Sol-Gel time processing, have been studied. Both, absorption and fluorescence spectra of the dye in the solid host, for different concentrations, show a blue-shift relative to its liquid phase.     

Kinetic study of the oxidation of some catecholamines by digital simulation of cyclic voltammograms

Electrochemical oxidation of some catecholamines such as dopamine ( 1 ), L ‐dopa ( 2 ), and methyldopa ( 3 ) has been studied in various pH values, using cyclic voltammetry. The results indicate participation of catecholamines ( 1–3 ) in intramolecular cyclization reaction to form the corresponding o‐quinone derivatives ( 1d–3d ). In various pHs, based on ECE mechanism, the observed homogeneous rate constants (k_obs) of cyclization reaction were estimated by comparing the experimental cyclic voltammetric responses with the digital‐simulated results. Also, the cyclization rate constants (k_cyc) were calculated using microscopic acidic dissociation constant of ammonium groups. The significant differences in electrochemical behavior, k_obs and k_cyc, of L ‐dopa ( 2 ) and methyldopa ( 3 ) with dopamine ( 1 ) are due to the effects of the side chain carboxyl group. © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 37: 17–24, 2005     

Hydrodynamics beyond Navier-Stokes: exact solution to the lattice Boltzmann hierarchy

The exact solution to the hierarchy of nonlinear lattice Boltzmann (LB) kinetic equations in the stationary planar Couette flow is found at nonvanishing Knudsen numbers. A new method of solving LB kinetic equations which combines the method of moments with boundary conditions for populations enables us to derive closed-form solutions for all higher-order moments. A convergence of results suggests that the LB hierarchy with larger velocity sets is the novel way to approximate kinetic theory.     

Synthesis and In Vitro Cytotoxic Activity of Novel Triazole‐Isoxazole Derivatives

New derivatives of triazole‐isoxazole were synthesized through a four‐step reaction starting from various ethyl 4‐aryl‐2,4‐dioxobutanoate derivatives. Finally, all compounds were examined by MTT assays for cytotoxic activity in two human breast cancer cell lines (MCF‐7 and T‐47D).     

Synthesis of Arylated Benzofurans by Regioselective Suzuki–Miyaura Cross‐Coupling Reactions of 2,3‐Dibromobenzofurans‐ and 2,3,5‐Tribromobenzofurans

Arylated benzofurans were prepared by regioselective Suzuki–Miyaura cross‐coupling reactions of 2,3‐dibromobenzofuran. The reactions proceeded with very good site‐selectivity in favor of the more electron deficient position 2. The Suzuki–Miyaura reactions of 2,3,5‐tribromobenzofuran also proceeded in favor of position 2.