Global warming has begun to affect Yakutia, an area recognized as the coldest region of the Northern Hemisphere. Previous research has indicated that the effects of global warming will be long-term. When modeling oncoming climatic changes, researchers often forecast the related water flow changes in various water bodies as well. However, these evaluations frequently differ from the actual water flow data. Thus, the current study identifies and assesses the trends in long-term flow fluctuations in the current context of global warming. This is particularly relevant in the subarctic region of Yakutia, because the local climate is not significantly influenced by anthropogenic factors. The region has an essentially uniform climate, and the river basins within the subarctic zone flow in the same direction. Thus, the study parameters can be adequately compared. Analysis of changes in the water regimen parameters of the rivers in this region is of particular importance. This study demonstrates that the changes in the long-term river regimen in the region, within approximately equivalent climate zones, have been highly and locally variable indifferent areas and time periods. However, we were unable to detect any specific consistency in these changes. The water content of almost all rivers in Yakutia has increased in the last 30 years (approximately), thus confirming general assumptions based on predictive models of climate changes; however, in most cases, such changes were the result of reaching the high-water stage of established long-term cycles. The nature of long-term fluctuations in the water flow of rivers did not change in about half of the Yakutia rivers. One water body showed a further decrease in the water content from the norm, both in terms of duration and water flow rate. Meanwhile, specific water bodies exhibited extreme long-term fluctuations, which are predicted to be a reaction to global warming. Prior to the onset of significant warming in the region, the trends of long-term water discharge fluctuations were stationary. Then, the trends of certain rivers became non-stationary due to the reasons indicated above. On their own, quantitative characteristics are insufficient to evaluate actual changes in water regimens. Moreover, evaluations obtained in the absence of a trend analysis of specific long-term discharge fluctuations, which can only be performed via graphic visualization, are most likely to be inaccurate.

Extraction of copper from the waste of the Karagayly concentrator under the action of an electric hydro-pulse discharge depending on the pH of the medium in the cell In the work, the waste of the Karagayly concentrator was processed at the experimental hydro pulse discharge (HPD) laboratory setup in order to transfer the copper contained in them (0.11-0.14 %) into the solution and then partially precipitate it in the process of pulsed electrolysis. Pulp from waste (waste + water 1:1) was poured into the cell, then an acidic medium was adjusted to the value pH = 1.0-3.0 using a mixture of reagents. Under the action of electro-hydro pulse the process of pulsed electrolysis occurs simultaneously. Then the lid was tightly closed and a hydro-pulse discharge (HPD) was performed for 5-20 minutes. Under the action of the discharge, all the metals contained in the pulp went into solution and simultaneously precipitated, except for copper ions, which remained in the solution and partially deposited on the cathode. As a result, after processing the pulp with HPD, 20 solutions with a precipitate were obtained. All solutions and precipitates were studied on a copper content by an atomic absorption spectrometer. The optimal conditions for the extraction of copper into solution, namely, the duration of discharge HPD for 20 minutes at pH = 1 and presence of silicate and phosphate ions, were established. All interfering ions of other metals remain in the sediment, since copper is to the right of other metals in the galvanic series.

Abstract. During the last years major progress in the reconstruction of the climatic and environmental history of Northern Eurasia has been made within the scope of the Russian-German project PLOT. The project aimed at investigating the regional responses of the quaternary climate and environment on external forcing and feedback mechanisms along a more than 6000 km long longitudinal transect crossing Northern Eurasia. The well-dated record from Lake El gygytgyn used as reference site for comparison the local climatic and environmental histories. Seismic surveys and sediment coring up to 54 m below lake floor performed on Ladoga Lake (North-West of Russia), Lake Bolshoye Shchuchye (Polar Ural), Lake Levinson-Lessing and Lake Taymyr (Taymyr Peninsula), Lake Emanda (Yana Highlands). Here, we present the major results of the project with a special focus on lake-level fluctuations and forcing mechanisms.

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This work is devoted to study of electrical properties, phases of LnM II CoO 3.5 (M II-Mg, Ca, Sr, Ba) which structure resembles to the structure of perovskite. The phases were obtained by solid-phase synthesis in accordance with the ceramic technology. The phase composition was determined by X-ray phase analysis. The diffractograms of the powders were indexed, the lattice parameters and its symmetry class were determined. It was found that the new compounds had a tetragonal symmetry, in the unit cell of which 16 structural units were located. Since complex oxides have high melting temperatures of about 1500-2000 ºC, it is impossible to obtain good quality single crystals suitable for measurements. For this reason, the study of their thermodynamic and electrophysical properties was carried out on samples in the form of sintered powders. In this study, the conductivity isotherms were measured by impedance spectroscopy at different temperatures. Resistance hodographs on the complex plane were constructed. Using the method of equivalent circuits, the grain boundaries and the bulk resistances of the sample grains were determined. The results showed that the new compounds had a small grain-boundary resistance. Using the temperature dependences, the activation energies of the conductivity of new cobaltites were calculated. The activation energy of conductivity for these compounds was 0.113-0.184 eV. The character of the dependence of the conductivity at moderate temperatures showed their thermal activation. In the Arrhenius coordinates, these sections of the graph were described by a straight line. An increase in the activation energy of the conductivity in the series of Mg 2+-Ca 2+-Sr 2+-Ba 2+ cations was observed. The introduction of an alkaline earth ion with a large ionic radius led to a local distortion of the crystal lattice. This changed the value of the splitting of the d-levels of the transition metal-cobalt. This change in the activation energy as the alkaline earth metal cation changes can be explained by the change in the width of the forbidden band. Also, the replacement of rare-earth elements ions with alkaline-earth metal ions led to a structural disorder, to an increase in the formation of equilibrium charged point defects in the crystal structure, in which the strength of the bond with trapped charge carriers by electrons or holes in point defects in the crystal lattice with different alkaline-earth ions was different.