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.     

The isotropy of Gaussian molecular networks and the stress-birefringence relations for rubberlike materials cross-linked in stressed states

Summary Using the model and some results of theJames andGuth theory of rabberlike elasticity, the relations between stress, birefringence, and strain (measured from the unstressed state) are re-derived by an argument which does not make use of certain assumptions used in previous derivations concerning the isotropy of the distribution of vectors joining junction mean positions and the fixing of junctions in their mean positions. It is proved that in the Gaussian approximation a rubberlike material is necessarily isotropic in the sense that the relations between the stress, strain, and refractive index involve no anisotropic constant tensors. The argument is applicable to networks whose junctions are introduced when the material is in different states of stress, and furnishes strong reasons for regarding the relations between flow birefringence and stress, previously derived on the basis of a network theory for concentrated polymer solutions, as being no longer restricted to solutions of constant viscosity.

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Zusammenfassung Unter Verwendung des Modells und einiger Ergebnisse der Theorie vonJames undGuth für Gummielastizit?t wurden die Beziehungen zwischen Spannung Doppelbrechung und Verformung (gemessen gegen den unbelasteten Zustand) erneut abgeleitet. Es wurde kein Gebrauch gemacht von den in früheren Ableitungen enthaltenen Annahmen über die Fixierung der Bindungen in mittleren Positionen und über die Isotropie der Verteilung der Vektoren, die diese Positionen verbinden. Es wird gezeigt, da? in derGauss-N?herung eines gummiartigen Materials Isotropie in dem Sinne erforderlich ist, da? die Beziehungen zwischen Spannung, Verformung und Brechungsindex keine anisotropen Tensoren der Konstanten enthalten. Diese Ableitung ist anwendbar auf Netzwerke, deren Bindungen eingeführt werden, w?hrend das Material in verschiedenen Spannungszust?nden vorliegt, und liefert eine gute Grundlage für die Annahme, da? die Beziehungen zwischen Str?mungsdoppelbrechung und Spannung, die früher auf Grund der Netzwerktheorie für konzentrierte Polymerenl?sungen abgeleitet wurden, nicht mehr auf L?sungen konstanter Viskosit?t beschr?nkt sind.

     

Synthesis of derivatives of pyrido[2,3-d]pyrimidines condensed with tetrahydropyran and tetrahydrothiopyran

Methods have been developed for obtaining derivatives of W-amino(oxo)-, 8,10-dioxo-, and 10-amino-8-oxo(thio)pyrano(thiopyrano) [4,3:4,5]pyrido[2,3-d]pyrimidine on the basis of 3-amino(benzylamino)-4-cyano (carbamoyl)pyrano(thiopyrano)[3,4-c]-pyridines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1683–1687, December, 1993.     

New approach to the synthesis of 3-amino-1,2-benzothiazine 1,1-dioxides

The possibility of obtaining 3-amino-1,2-benzothiazine 1,1-dioxides by nucleophilic substitution of the chlorine atom in 5-nitro-2-chlorobenzenesulfonamides by carbanions generated from substituted acetonitriles was studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 264–266, February, 1992.     

Recyclization of 3-phenacylidene-3,4-dihydro-2H-1,4-benzoxazin-2-one under the influence of o-phenylenediamine

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, p. 856, June, 1991.