Fuzzy Linear Programming Approach for Solving Fuzzy Transportation Problems with Transshipment

To find the fuzzy optimal solution of fuzzy transportation problems it is assumed that the direct route between a source and a destination is a minimum-cost route. However, in actual application, the minimum-cost route is not known a priori. In fact, the minimum-cost route from one source to another destination may well pass through another source first. In this paper, a new method is proposed to find the fuzzy optimal solution of fuzzy transportation problems with the following transshipment: (1) From a source to any another source, (2) from a destination to another destination, and (3) from a destination to any source. In the proposed method all the parameters are represented by trapezoidal fuzzy numbers. To illustrate the proposed method a fuzzy transportation problem with transshipment is solved. The proposed method is easy to understand and to apply for finding the fuzzy optimal solution of fuzzy transportation problems with transshipment occurring in real life situations.     

New Polymer‐Supported Mono‐ and Bis‐Cinchona Alkaloid Derivatives: Synthesis and Use in Asymmetric Organocatalyzed Reactions

The straightforward synthesis of polystyrene‐supported Chinchona alkaloids and their application in the asymmetric dimerization of ketenes is reported. Six different immobilized derivatives, consisting of three dimeric and two monomeric 9‐O ethers, were prepared by “click” anchoring of soluble alkaloid precursors on to azidomethyl resins. The resulting insoluble polymer‐bound (IPB) organocatalysts were employed for promoting the dimerization of in‐situ generated ketenes. After opening of the ketene dimer intermediates with N,O‐dimethylhydroxylamine, valuable Weinreb amides were eventually obtained in good yield (up to 81 %) and excellent enantiomeric purity (up to 96 % ee). All of the IPB catalysts could be recycled effectively without significant loss of activity and enantioselectivity. The extension to other asymmetric transformations (meso‐anhydride desymmetrization and α‐amination of 2‐oxindoles) is also briefly discussed.     

Low temperature deposition of SrS:Cu,F ACTFEL device by electron beam evaporation

Photoluminescence (PL) and electroluminescence (EL) of SrS:Cu,F alternating current thin film electroluminescent (ACTFEL) device prepared by electron beam/thermal multi-source evaporation are presented. The active layer was grown at 380 °C and neither post-deposition annealing nor sulphur co-evaporation was performed. Two bands at 380 and 435 nm were present in the PL spectrum, which are suggested to be due to donor acceptor recombination. EL spectrum consisted of an additional band at 535 nm, which is attributed to Cu⁺ intracenter emission. The device exhibited yellowish white EL emission with chromaticity coordinates x=0.25, y=0.27 and low threshold voltage.     

Ring closing and opening reactions leading to aza-polycyclic aromatic compounds

A series of functionalized aza-polycyclic aromatic compounds were prepared by a superacid-promoted ring closing and opening reaction cascade. A reaction mechanism is proposed, which involves reactive dicationic intermediates. A key step in the conversions involves ipso protonation of an aryl group and elimination of an alkyl phenyl group.     

An Efficient Inclusion Complex Based Fluorescent Sensor for Mercury (II) and its Application in Live-Cell Imaging

Journal of Fluorescence - The formation of an inclusion complex between hydroxypropyl-β-cyclodextrin (H-CD) and 4-acetylphenyl-4-(((6-chlorobenzo[d]thiazol-2-yl)-imino)-methyl)-benzoate (L)...     

Ring closure of diethyl 2-methoxy-2-[N-(5-amino-1-benzylimidazolyl-4-carbonyl)amino]malonate: Product structures and pathways of product formation

Ring closure of the title compound (1) with sodium methoxide in methanol yielded three products, one 56-fused and two 57-fused heterocyclic systems: 9-benzyl-2-methoxycarbonylhypoxanthine (2), 3-benzyl-4,5,7,8-tetrahydro-6-methoxy-6-methoxycarbonyl-6H-imidazo[4,5-e][1,4]-diazepine-5,8-dione (3), and 3-benzyl-4,5,7,8-tetrahydro-6-methoxy-6H-imidazo[4,5-e][1,4]-diazepine-5,8-dione (4). Structures and pathways of formation of all three products have been described. Structures of2 and3 were confirmed by single-crystal X-ray diffraction analyses.     

UV curable waterborne polyurethane acrylate dispersions based on hyperbranched aliphatic polyester: effect of molecular structure on physical and thermal properties

A novel waterborne hyperbranched polyurethane acrylate for aqueous dispersions (WHPUDs) based on hydroxy‐functionalized hyperbranched aliphatic polyester Boltorn? H20 was investigated. The effects of structural composition and crosslinking density have been studied in terms of swellability by water, thermal degradation, viscosity changes as well as transmission electron microscopy (TEM) morphology. The swell ratio showed an increasing trend with the higher concentration of ionic group, which is due to the increased total surface area of particles. The results of thermogravimetric analysis (TGA) for cured WHPUD films indicated good thermal stability with no appreciable weight loss until 200°C. The activation energies were evaluated and were found in the range 154–186 kJ mol^?1. It was observed that an increase in hard segment content provoked the increases in thermal degradation temperature and activation energy of waterborne dispersions. The transmission electron photographs revealed that the average particle sizes of aqueous dispersions were in the range 30–125 nm. Owing to the enlargement of the stabilization site, the particle size decreased as the content of carboxyl group and degree of neutralization increased. The viscosity of WHPUDs increased rapidly with increasing the degree of neutralization. Moreover, water showed a favorable viscosity reduction effect. Copyright © 2004 John Wiley & Sons, Ltd.