The paper aims to test the hypothesis whether high tariffs lead to a high efficiency of electricity suppliers. The authors test this hypothesis on a case of 29 Ukrainian electricity distribution companies. Using the data envelopment analysis and correlation coefficients, grouping the super-efficiency scores, the authors found that in most regions of Ukraine the increase in tariffs no longer leads to increased efficiency. This indicates a weakness of tariff policy in most of the electricity distribution companies. The case showed that rising tariffs can cause a decline in revenue, net income and an increase in accounts payable. This does not allow the electricity distribution companies to provide high efficiency.

Apart from this, despite improving the financial performance of most companies, the electricity distribution industry in Ukraine as a whole remains unprofitable. However, the high percentage of foreign investors in this industry indicates a significant potential for increasing the efficiency of Ukrainian energy companies. The government control of the electricity distribution companies more often provides medium efficiency, while the management by foreign investors often provides a high efficiency. The absence of the major owner and the presence of blocking stakes in any investor (government, domestic or foreign investors) has a negative impact on the efficiency of energy companies.

Although the case is limited to one country and 29 companies, this study can serve as a model for wider testing of the research hypothesis in other markets and countries.

The issues discussed in the paper concern the assessment of changes in quantitative and qualitative indicators of water resources in the climatic conditions of the southern part of Kazakhstan. For this purpose, many years of systematic field observations and other continuous data obtained from the functioning measurement and observation stations operating within the Aral-Syrdarya Basin Inspection were used. On the basis of the obtained data, indicators were determined that characterize the quantity and quality of water supplied to the soil in the irrigation process, as well as the quantity and quali-ty of water flowing out of the drainage systems, together with an evaluation of the effectiveness of irrigation and drainage systems. Soil salinity was assessed in five irrigated massifs with a total area of 332.55 thous. ha. For the same irrigated massifs, the annual amounts of water taken for irrigation, the amount of outflowing water and the assessment of the miner-alization level were determined. Based on the developed results of field observations characterizing the hydrological and environmental situation of the lower section of the Syr Darya River in 1960–2015, the negative reaction coefficients were calculated for the local population, soil and vegetation for five of the irrigated massifs of the Kyzylorda region. The ecolog-ical situation of the habitat of soil and plants in the lower reaches of the Syr Darya River in all irrigation areas deteriorates on a time scale, since as a result of the reclamation of agricultural lands, intensive secondary soil salinization occurs and the formation of infiltration runoff with high mineralization, contributing to the violation of the harmonization of the relation-ship between nature and man.

One of the ways to decrease thermal conductivity is nano structurization. Cobalt triantimonide (CoSb3) samples with added indium or tellurium were prepared by the direct fusion technique from high purity elements. Ingots were pulverized and re-compacted to form electrodes. Then, the pulsed plasma in liquid (PPL) method was applied. All materials were consolidated using rapid spark plasma sintering (SPS). For the analysis, methods such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM) with a laser flash apparatus (LFA) were used. For density measurement, the Archimedes’ method was used. Electrical conductivity was measured using a standard four-wire method. The Seebeck coefficient was calculated to form measured Seebeck voltage in the sample placed in a temperature gradient. The preparation method allowed for obtaining CoSb3 nanomaterial with significantly lower thermal conductivity (10 Wm^–1K^–1 for pure CoSb₃ and 3 Wm^–1K^–1 for the nanostructured sample in room temperature (RT)). The size of crystallites (from SEM observations) in the powders prepared was about 20 nm, joined into larger agglomerates. The Seebeck coefficient, α, was about –200 µVK^–1 in the case of both dopants, In and Te, in microsized material and about –400 µVK^–1 for the nanomaterial at RT. For pure CoSb3, α was about 150 µVK^–1 and it stood at –50 µVK^–1 for nanomaterial at RT. In bulk nanomaterial samples, due to a decrease in electrical conductivity and inversion of the Seebeck coefficient, there was no increase in ZT values and the ZT for the nanosized material was below 0.02 in the measured temperature range, while for microsized In-doped sample it reached maximum ZT = 0.7 in (600K).