Solution of the Falkner–Skan equation for wedge by Adomian Decomposition Method

The Adomian Decomposition Method is employed in the solution of the two dimensional laminar boundary layer of Falkner–Skan equation for wedge. This work aims at the solution of momentum equation in the case of accelerated flow and decelerated flow with separation. The Adomian Decomposition Method is provided an analytical solution in the form of an infinite power series. The effect of Adomian polynomials terms is considered on accuracy of the results. The velocity profiles in boundary layer are obtained. Results show a good accuracy compared to the exact solution.     

Quark masses and flavor-mixing angles in a six-quark model of quantum flavordynamics

The Cabibbo-like flavor-mixing angles are related to quark masses through spontaneous symmetry breaking in an illustrative model of quantum flavordynamics based on the SU_2L x SU_2R x U₁ flavor gauge group and on six quark flavors. Theoretical and experimental consequences of the scheme are discussed.     

Hierarchy of masses for pseudoscalar and vector mesons

Assuming that quark flavors beyond isospin, strangeness, and charm exist, we use the relationship between the structure of chiral symmetry breaking of the strong interaction and the Cabibbo angle in order to estimate the masses of the pseudoscalar and vector mesons carrying the fifth (beauty), sixth (truth), and seventh (illusion) quark flavors.     

Interaction of an intermediate structure of Bacillus subtilis α-amylase with alkyl-substituted sepharose 4B

An intermediate form of alpha-amylase from Bacillus subtilis was prepared following a previously reported procedure. Stabilization of this protein structure by various additives and its interaction with alkyl-substituted Sepharose 4B (Sepharose-lipid), used to mimic the role of the alkyl chains of the phospholipid bilayer, were investigated. Exposure of hydrophobic clusters in the protein structure on denaturation was indicated by a greater affinity of the intermediate form for interaction with the alkyl chains on the matrix, as compared with the original native structure. Near- and far-ultraviolet circular dichroism studies supported loss of tertiary structure with retention of secondary structure, as expected from molten globular intermediate forms. Based on the results presented, we suggest that interaction of a protein in its native and nonnative forms with an alkyl-substituted matrix may provide useful information regarding its capacity for insertion into and translocation across the biologic membrane.     

Preparation of triblock styrene–tert-butylstyrene–styrene copolymers by living radical polymerization with a heterogeneous polymeric initiator

Triblock copolymers containing the sequence styrene, p-tert-butylstyrene, styrene were prepared in an emulsion system by using isotactic polypropylene hydroperoxide as the initiator together with triethylenetetramine as an activator, according to the method of Mikulasova and co-workers. Polymerization of styrene continued after removal of the initiator from the emulsion by filtration and eventually reached 100% conversion after 4 hr at 35°C. tert-Butylstyrene at 80°C and styrene at 35°C were added successively to the system, with each polymerization reaction carried to 100% conversion before the next monomer was added. Thin-layer chromatography was used to separate the homopolymers and block copolymers in order to determine the purity of the product. Monomer compositions of the block copolymers was verified by infrared analysis. The existence of two separate phases in the extracted block copolymer was indicated by the observation of two distinct glass transition temperatures.     

The effect of corrugation of pore wall on the thermal diffusion in nanopores by molecular dynamics simulations

In this work we have studied the effect of corrugation on the thermal diffusion (soret effect) in isotopic and non-isotopic fluid mixtures confined in a slit pore. We used a boundary driven non-equilibrium molecular dynamics to simulate thermal diffusion in Lennard–Jones (LJ) binary mixtures confined in structureless Steele 10-4-3 and atomistic Lennard–Jones pore walls. The results showed that for the isotopic mixture thermal diffusion factor for both wall types agrees and the corrugation of the LJ wall has no effect in isotopic mixture. However, for non-isotopic mixture confined in atomistic LJ pore the component with stronger attraction adsorbs more to the wall than the structureless Steele wall. The effect of corrugation of pore wall on the thermal diffusion is noticeable in narrow slit pore and mixture with large difference in molecular attraction parameter of components.     

CONVERSION OF EPOXIDES INTO 2-HYDROXYETHYL THIOCYANATES WITH NH4SCN IN THE PRESENSE OF 2,6-BIS[2-(O -AMINO PHENOXY)METHYL]-4-BROMO-1-METHOXYBENZENE (BABMB) AS CATALYST

A convenient and efficient procedure for the ring-opening of 1,2-epoxyethanes with ammonium thiocyanate in the presence of 2,6-bis[2-(o -aminophenoxy)methyl]-4-bromo-1-methoxybenzene (BABMB) is described. In this study, a reagent and conditions have been discovered with which the individual 2-hydroxyethyl thiocyanates can be synthesized in high yield and with more than 90% regioselectivity. Thus, several 2-hydroxyethyl thiocyanates, useful intermediates toward biological-active molecules, are easily obtained in very good yields.