Excess Enthalpies of Mixing of Binary Mixtures of NaCl, KCl, NaBr and KBr in Mixed Ternary Solvent Systems at 298.15 K

Excess enthalpies of mixing for six possible binary combinations of solutions of NaCl, KCl, NaBr and KBr in mixed ternary solvents composed of formamide, 1,4-dioxane and water have been determined using a flow microcalorimeter at constant ionic strengths of 0.500 and 1.000 mol kg–1 at 298.15 K. Unlike the case of water, the data do not supportYoung’s cross square rule. Pitzer’s virial coefficient theory has been utilized to obtain binary and ternary interaction parameters, i.e. θH and ψH. The data were also analysed in terms of the Friedman model and it was found that interactions between solvated ions are dictated not only by coulombic interactions but also by appreciable asymmetric effects.Keywords: Enthalpy of mixing, ternary solvents, Pitzer theory, Friedman model, cross square rule

Belagash: A Newly Discovered Kipchak-Era Site in Central Kazakhstan

Introduction. Despite the long history of archaeological research in Central Kazakhstan, many aspects of culture inherent to its medieval nomadic population remain understudied. So, the ninety-year-long excavations of eighth-to-twelfth century sites have shaped certain ideas about the latter primarily on the basis of statuary objects and thirteen sanctuary-type facilities with varying structural patterns. Funeral rites can be traced only in one attributed burial discovered in cultural layers of the Bronze Age settlement of Kent. Goals. The study attempts a complete historical summary of investigations into eighth-to-twelfth century sites across Central Kazakhstan, and introduces into scientific circulation some newly discovered material from the site of Belagash. Materials and methods. All the studied objects of Belagash are rather similar graveside structures in the form of unsodded stone mounds sized 2–3 to 13 m. Unfortunately, facilities nos. 1–3 were looted and have yielded only scarce finds that provide insufficient data for any reconstruction of rituals. And since such graveside structures can to some extent be traced in both Early Iron Age and medieval monuments, the question of their dating shall be left open for the time being. Results. Facility no. 4 is of utmost interest. Its formal typological features attest to it may cluster with eighth/ninth-to-eleventh century sites. It was containing some scattered horse remains accompanied by an iron stirrup, a buckle, a bronze belt tip, and an appliqué plaque. Typological characteristics of the stirrup are crucial to identifying the historical period in question: analogues from the Irtysh River valley and the Altai may date the investigated site to the eighth/ninth throughout eleventh centuries CE. Conclusions. It is urgent to emphasize the significance of the material from Belagash since the latter does add to the meager data on the culture of Central Kazakhstan’s population at the final stage of the Early Middle Ages