the use of recycled bassanite, produced from gypsum wastes, in ground improvement projects is initiated recently in japan to eliminate the huge quantities of gypsum wastes. meanwhile the use of recycled bassanite has a positive effect on the environment and economy, it has many challenges. these challenges are related to the release of fluorine more than the standard limits results in contamina...

Three hundred and five coal samples were taken from the main coal mines of twenty-six provinces, autonomous regions, and municipalities of China. The method of pyrohydrolysis was applied to measure the fluorine content in the samples, which exhibit logarithmic normal frequency distributions. The range of fluorine content in dry coal varies from 25 to 1230 mg/ kg with a geometric mean of 136 mg/...

Before the rationing of tea was introduced, New Zealand had the third largest annual consumption of tea in the world, namely 8.2 Ib./person. Subsequently, the ration of 2 oz./wcek with extra concessions to people working in factories and offices provided an annual consumption of 6-5 lb./person. Most foods are found to be poor sources of fluorine, even when grown in fluorinerich soils, supposedl...

A new polyfluorinated anti-staining coating material CF3O(CF2CF2O)xCF2-CONHCH2CH2CH2Si(OCH3)3 has been developed by utilizing the PERFECT method, which employs a liquid-phase direct fluorination reaction with elemental fluorine as a key step. Direct fluorination of a partially-fluorinated ester, which was prepared from a non-fluorinated poly(ethylene glycol) and a perfluorinated acyl fluoride, ...

A convenient one-pot approach to alkylcyanobiaryls is described. The method is based on biaryl cross-coupling between the sodium salt of the terephthalonitrile dianion and a neutral aromatic nitrile in liquid ammonia, and successive alkylation of the long-lived anionic intermediate with alkyl bromides. The reaction is compatible with benzonitriles that contain methyl, methoxy and phenyl groups,...

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The synthesis and characterization of new 2,2-difluorovinyloxyl terminated tolane liquid crystals are reported. The mesomorphic properties, mid-wave infrared (MWIR) absorption and birefringence were investigated. The results show that these materials exhibit low absorption loss, a wide nematic phase range, a low melting point and high birefringence. The influences of fluorine substitution and t...

It is shown that the proton NMR spectra of molecules containing rare spins at natural abundance dissolved in a liquid crystalline solvent can be obtained free from the strong lines from the spectrum of the abundant isotopomer by the 2D HSQC NMR experiment. The technique can also give the individual chemical shifts of the rare spins, and, for a molecule containing another abundant nucleus, such ...

Perfluorocarbons are a family of molecules consisting mainly of carbon and fluorine atoms. They have interesting chemical properties and have diverse applications in biomedicine, physical chemistry and polymer science. In this work, carbon K-edge absorption and emission spectra of liquid decalin are presented and compared to perfluorodecalin. A comprehensive picture of the electronic structure ...

Liquid-crystal phases with both solid and liquid characteristics are unique, since they exhibit chirality on both molecular and mesoscopic levels under special circumstances. We have studied binary composites formed by mixing of a chiral dimer (B-Ch), in which a bent core is covalently linked to a promesogenic cholesterol unit through a flexible spacer, and an achiral bent-core mesogen having t...