Preliminary analyses of natural radionuclides in selected Turkish power plant lignites

This preliminary study presents the experimental results concerning the concentrations of selected radionuclides (²³⁸U, ²³²K, ²²⁶Ra, ²³²Th) in Af?in-Elbistan, Çan, Çay?rhan, Erzurum, Göynük, Kangal, Orhaneli, Saray, Seyitömer, Soma, Tunçbilek, Yata?an and Yeniköy lignites, which are primarily utilized as fuel for thermal power plants in Turkey. Gamma-spectrometry of 39 representative lignite samples gave results with the following concentration ranges: 8 to 296 Bq/kg for ²³⁸U, 3 to 79 Bq/kg for ²³²Th, 17 to 360 Bq/kg for 40K, and 5 to 130 Bq/kg for ²²⁶Ra. The ²³⁸U results reported here are higher than other literature values for various world coals, earth's crust and world average.     

Crystal structure of the oxime of 2-acetylpyridine

Institute of Chemical Physics, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 3, pp. 113–115, May–June, 1991.     

Chimie des complexes de metaux de transition avec des hydrocarbures cyanes : III. Quelques observations sur la conformation et la reactivite de complexes dicyclopentadienyles du molybdene et du tungstene

A new class of cyclic telluronium salts has been prepared. All the salts are stable in solution in CHCl₃ or dimethylsulphoxide (DMSO). Conductivity measurements in DMSO and dimethylformamide (DMF) have shown that considerable ion pairing occurs in solution. Infrared, ¹H, ¹³C, ¹²⁵Te NMR, and mass spectra are reported and discussed.     

Origin of the lower critical flocculation temperature in polymer colloids stabilized by polydimethylsiloxane

Summary It has recently been reported (6, 7) that poly(methyl methacrylate) particles that are sterically stabilised by polydimethylsiloxane flocculate on cooling when dispersed in short chain n-alkanes. Since the LCFT was reported to be essentially independent of the nature of the dispersion medium, it was postulated (2) that incipient flocculation of these particles was caused by crystallisation of the polydimethysiloxane chains, which would have allowed the attractive van der Waals forces to become operative. This hypothesis has now been confirmed by low temperature X-ray studies.

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Zusammenfassung Von (6, 7) wurde kürzlich mitgeteilt, daß Poly(methylmethacrylat)-Teilchen, die mit Polydimethylsiloxan sterisch stabilisiert sind, in kurzkettigenn-Alkanen als Dispersionsmittel ausflocken. Da die LCFT im wesentlichen unabhängig von der Natur des Dispersionsmediums ist, wurde von (2) angenommen, daß die beginnende Ausflockung dieser Teilchen auf eine Kristallisation der Polydimethylsiloxan-Ketten zurückzuführen ist, bedingt durch die wirkenden van der Waals-Anziehungskräfte. Diese Hypothese wurde nun durch Röntgenuntersuchungen bei tiefer Temperatur bestätigt.

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