C *-Ternary 3-Homomorphisms on C *-Ternary Algebras

In this paper, we investigate the Ulam-Hyers stability of C ^*-ternary algebra 3-homomorphisms for the functional equation $$f(x_1 + x_2 + x_3, y_1 + y_2 + y_3, z_1 + z_2 + z_3) = \sum_{1\leq i,j,k\leq 3} f(x_i, y_j, z_k)$$ in C ^*-ternary algebras.     

On the Movement of Transitive Permutation p-Groups

Let G be a transitive permutation group on a set and m a positive integer. If | – | m for every subset of and all g G, then || 2mp/(p – 1) where p is the least odd prime dividing |G|. It was shown by Mann and Praeger [13] that, for p = 3, the 3-groups G which attain this bound have exponent p. In this paper we will show a generalization of this result for any odd primes.AMS Subject Classification (2000), 20BXX     

Incompressible Roe‐like scheme for turbulent flows

In the current study, numerical investigation of incompressible turbulent flow is presented. By the artificial compressibility method, momentum and continuity equations are coupled. Considering Reynolds averaged Navier–Stokes equations, the Spalart–Allmaras turbulence model, which has accurate results in two‐dimensional problems, is used to calculate Reynolds stresses. For convective fluxes a Roe‐like scheme is proposed for the steady Reynolds averaged Navier–Stokes equations. Also, Jameson averaging method was implemented. In comparison, the proposed characteristics‐based upwind incompressible turbulent Roe‐like scheme, demonstrated very accurate results, high stability, and fast convergence. The fifth‐order Runge–Kutta scheme is used for time discretization. The local time stepping and implicit residual smoothing were applied as the convergence acceleration techniques. Suitable boundary conditions have been implemented considering flow behavior. The problem has been studied at high Reynolds numbers for cross flow around the horizontal circular cylinder and NACA0012 hydrofoil. Results were compared with those of others and a good agreement has been observed. Copyright © 2012 John Wiley & Sons, Ltd.     

Selective and Efficient Oxidation of Aldehydes to Their Corresponding Carboxylic Acids Using H2O2/HCl in the Presence of Hydroxylamine Hydrochloride

A wide variety of aldehydes were efficiently converted to their corresponding carboxylic acids in high yields using H₂O₂/HCl in the presence of hydroxylamine hydrochloride. In addition, selective oxidation of aldehydes in the presence of other functional groups such as hydroxyl group, carbon‐carbon double bond and other heteroatoms can be considered a noteworthy advantage of this method.     

Synthesis of WO2pyprMCM-41 as selective and reusable catalyst for the epoxidation of alkenes

The sythesis, characterization and catalytic activity of WO₂pypr [N,N′-bis (2-pyrrolmethlidenaminopropyl) amine] complexed to MCM-41 surface in the epoxidation of some alkenes with excellent selectivity toward the corresponding epoxides is described in this presentation.     

Self‐diffusion coefficients obtained from proton‐decoupled carbon‐13 spectra for analyzing a mixture of terpenes

In the limit of sufficient sensitivity, natural abundance ¹³C offers a much better spectral resolution than proton NMR. This is due to an important chemical shift range and to proton‐decoupling conditions that yield one peak per carbon with practically no overlap. However, pulsed gradient spin echo experiments, which lead to the diffusion coefficient associated with each peak, have scarcely been employed. In this article, we present and compare different ways to access this quantity and we have effectively verified that, without any precaution, diffusion coefficients cannot be properly determined from standard procedures. The cause of such a failure is decoupling during the gradient pulses. We have used a very simple remedy that proved to be very successful on a model mixture of three monoterpenes and that appears as being of general applicability. Copyright © 2009 John Wiley & Sons, Ltd.     

On the sphericity testing of single source digraphs

A digraph D=(V,A) is called spherical, if it has an upward embedding on the round sphere which is an embedding of D on the round sphere so that all edges are monotonic arcs and all point to a fixed direction, say to the north pole. It is easy to see that [S.M. Hashemi, Digraph embedding, Discrete Math. 233 (2001) 321-328] for upward embedding, plane and sphere are not equivalent, which is in contrast with the fact that they are equivalent for undirected graphs. On the other hand, it has been proved that sphericity testing for digraphs is an NP-complete problem [S.M. Hashemi, A. Kisielewicz, I. Rival, The complexity of upward drawings on spheres, Order 14 (1998) 327-363]. In this work we study sphericity testing of the single source digraphs. In particular, we shall present a polynomial time algorithm for sphericity testing of three connected single source digraphs.