Multidisciplinary Study of Burnt Deposits at Surungur, Fergana Valley, Southern Kyrgyzstan

Burnt deposits are an important source of information on ancient lifestyles, providing the possibility of reconstructing the size, intensity of use, and functions of fi replaces at prehistoric settlements, and to assess fuel sources. We outline the results of a multidisciplinary study of fi replaces and their contexts at Surungur—a stratifi ed site in the Fergana Valley, in southern Kyrgyzstan. Sixteen samples from ash lenses and intermediate deposits were studied by rock-magnetism, gas chromatography mass spectrometry (GC-MS), and X-ray fl uorescence (XRF). The rock-magnetic analysis suggests that the origin of all samples from ash lenses was anthropogenic. Types of fuel were reconstructed. At the initial stage (Early Holocene), the encompassing deposits likely resulted from short-term occupation, and fuel consisted of wood and grass/ dung. In the Middle Holocene, occupation became more long-term, as evidenced by maximal heating temperatures and high concentration of fi replaces. During the Late Holocene, habitation intensity on the platform under the stone ledge remained the same, but heating was less intense. Wood and grass/dung were used as fuel at all stages, suggesting that wood was available in the region throughout the Holocene.

Phase Transition in Niobophosphate Glass-Ceramic

Phase transition during crystallization of glass to glass-ceramic in system P2O5-CaO-Nb2O5-Na2O was studied. Several heating rates were compared – 1, 2, 5, 11 and 20°Cmin-1. DTA, XRD, FTIR and Raman analyses were performed. Niobophosphate glass-ceramic is found to form utterly different crystalline phases depending on maximal heating temperature, heating rate and time of maximal temperature maintenance. Crystallization temperatures of the same phases are strongly dependent on heating rate, while crystallinity of obtained phases is not. At lower temperatures poorly crystalline phosphates (Ca3(PO4)2, Ca10Na(PO4)7, Ca2P2O7) and niobates (NaNbO3 and Nb2O5) are identified. At higher temperatures a large amount of well crystalline niobophosphate (Na4(Nb8P4O32) and Ca2P2O7 forms. With increasing amount of Na4(Nb8P4O32), amount of NaNbO3 and Nb2O5 decreases.

AN EXPERIMENTAL STUDY OF DIATHERMY

The principles governing the passage of high frequency currents through various conductors have been discussed and exemplified in experiments done on both non-living and living bodies. In Part I it was shown: (1) That the current takes the path of least electrical resistance rather than the shortest path; (2) that maximal heating occurs at the point of greatest concentration of the lines of current flow. In a homogeneous medium with parallel electrodes maximal heat production occurs in those portions of the medium adjoining the electrodes and the heat gradient is from without inward. Under these circumstances maximal heating never occurs at the center. In discussing the localization of heat not only the electrical resistance and current concentration, but also the cooling effect, must be considered. In experiments on the dog's cadaver no evidence of the so called "skin effect" could be demonstrated. This is in contradistinction to the findings of Bettman and Crohn, but the discrepancy is explained on the basis of what we believe to be a technical error in their work. The finding of no "skin effect" is in agreement with the conclusions of Dowse and Iredell, based on both experimental and theoretical considerations. In Part II three types of experiments were performed on the anesthetized dog. The conclusions to be derived from them are these: (1) The heat gradient of the body is reversed during diathermy and heating occurs from without inward; (2) deep heating during diathermy is greater than that which results from the application of local heat to the skin; (3) the lung can be heated by diathermy in spite of simultaneous cooling of the chest wall. These experiments we regard as satisfactory evidence of the passage of the current through the interior of the body.