Developing a novel alkaline anion exchange membrane derived from poly(ether‐imide) for improved ionic conductivity

We have developed a novel alkaline anion exchange membrane derived from poly(ether‐imide) for improved ionic conductivity. The effects of several important parameters on the chloromethylation of the membrane were investigated. These parameters included reaction temperature, reaction time, concentration of chloromethylation agent, concentration of polymer, and the amount of catalyst. The quaternization of the synthesized chloromethylated polymer was studied as well. The results show that all the studied parameters exhibited significant impacts on chloromethylation. Among them, the concentration of the chloromethylation agent played a key role in increasing the chloromethyl functional group attachment onto the polymer. It was found that the gelation could be avoided if these reaction parameters were controlled. It was also found that using an appropriate quaternization approach could significantly improve the ionic conductivity and optimize the conductivity of the membrane even though the functional chloromethyl groups attached to the polymer are limited. Copyright © 2009 John Wiley & Sons, Ltd.     

A genetic algorithm for the two-stage supply chain distribution problem associated with a fixed charge

This paper considers a two-stage distribution problem of a supply chain that is associated with a fixed charge. Two kinds of cost are involved in this problem: a continuous cost that linearly increases with the amount transported between a source and a destination, and secondly, a fixed charge, that incurs whenever there exists a transportation of a non-zero quantity between a source and a destination. The objective criterion is the minimisation of the total cost of distribution. A genetic algorithm (GA) that belongs to evolutionary search heuristics is proposed and illustrated. The proposed methodology is evaluated for its solution quality by comparing it with the approximate and lower bound solutions. Thus, the comparison reveals that the GA generates better solution than the approximation method and is capable of providing solution either equal or closer to the lower bound solution of the problem.     

Chemical bonding in view of electron charge density and kinetic energy density descriptors

Stalke's dilemma, stating that different chemical interpretations are obtained when one and the same density is interpreted either by means of natural bond orbital (NBO) and subsequent natural resonance theory (NRT) application or by the quantum theory of atoms in molecules (QTAIM), is reinvestigated. It is shown that within the framework of QTAIM, the question as to whether for a given molecule two atoms are bonded or not is only meaningful in the context of a well‐defined reference geometry. The localized‐orbital‐locator (LOL) is applied to map out patterns in covalent bonding interaction, and produces results that are consistent for a variety of reference geometries. Furthermore, LOL interpretations are in accord with NBO/NRT, and assist in an interpretation in terms of covalent bonding. © 2008 Wiley Periodicals, Inc.J Comput Chem, 2009.     

Predicting DAX trends from Dow Jones data by methods of the mathematical theory of democracy

The mathematical theory of democracy operates on the indices of popularity and universality which are used to find socially optimal representatives and representative bodies. Regarded mathematically, neither the ‘society’, nor its ‘representatives’ are necessarily human, so that some objects can represent the behavior of other objects. This idea is applied to predicting the DAX-trends (German stock index) from the actual Dow-Jones data; the current fluctuations of stock prices in New York are regarded as representative indicators of future stock price fluctuations in Frankfurt. In particular, it is found that American Express anticipates on the average the price ±fluctuations of 2/3 of the DAX stocks. The statistical significance of the null hypothesis that such a bias from the uncertainty 50% can occur by chance is only 3.5%.     

Mechanistic study on dimerization of acetylene with a Nieuwland catalyst

A mechanistic study on the Nieuwland catalysis for dimerization of acetylene is performed by detecting copper–acetylene and copper–monovinylacetylene π‐complexes and also by examining the kinetics under virtually the same reaction conditions employed in the industrial process. An efficient H/D exchange occurs between acetylene and protons in the Nieuwland catalytic system. Addition of a coordinating ligand to the conventional Nieuwland catalytic system results in improvement of the catalytic activity and selectivity for the acetylene dimerization. The kinetic analysis including the kinetic deuterium isotope effect provides valuable insight into the Nieuwland catalytic mechanism of the dimerization of acetylene. Copyright © 2008 John Wiley & Sons, Ltd.     

Transfer of electron density as a result of hydrogen bond formation

It has been found that the amount of charge transfer between donor and acceptor molecules in four sets of hydrogen‐bonded complexes may be adequately described as an exponential function of the equilibrium distance between the hydrogen atom and the nearest atom of the acceptor molecule. The exponential factors of the transfer are of the same order but somewhat larger than the factors found otherwise in the investigations of dynamic electron transfer. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009     

Stabilization of 1,2-ditellurolane by 2,3,5,6-tetramethylnitrosobenzene (Nitrosodurene)

1,2-Ditellurolane is an extremely unstable heterocyclic compound which can be maintained in solution in the presence of nitrosodurene for several days. It is proposed on the basis of UV spectroscopy and ¹H NMR spectroscopy that a complex is formed which determines the stability of 1,2-ditellurolane. It is shown that stabilized 1,2-ditellurolane can be used in organic synthesis. Presented to Academician of the Russian Academy of Sciences Boris Aleksandrovich Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, 1736–1738, November, 2008.