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Over 900 event-based precipitation samples were collected in 2019–2021 in the Tien Shan and its foothills and analysed using cavity ring-down spectroscopy. δD and δ18O values were highest in summer and lowest in winter, and annual cycles of deuterium excess (d-excess) varied between sites, reflecting local conditions. The δ18O and δD values increased from north to south in all seasons except autumn, and latitude was a statistically significant predictor of δ18O and δD in the overall data set, along with elevation in winter and elevation and longitude in autumn. Elevation was a significant predictor of d-excess in all seasons, and local air temperature was a more important control over δ18O and δD than precipitation depth. Local meteoric water lines were derived using seven regression methods applied to non-weighted and weighted precipitation. Non-weighted ordinary least squares regression and reduced major axis regression methods are recommended overall, except for summer when the precipitation-weighted least squares regression should be used, particularly in the south. Atmospheric back-trajectory and mixing-model analyses were applied in combination to identify air mass source regions and their relative contribution to precipitation. Recycled moisture from irrigated land in the Amu Darya and Syr Darya basins and from the study catchments accounted for 29 %–71 % of precipitation, depending on the site and season. In the Chon Kyzyl-Suu catchment, local re-evaporation from Issyk-Kul accounted for up to 85 % of precipitation. These findings highlight the importance of moisture from terrestrial sources, especially irrigated land, for the formation of precipitation in the Tien Shan.

In this work, a porous nickel anode for thin-film solid oxide fuel cell prepared by the simple powder hot-pressing method is investigated. Powders of Ni and pore-forming agent (PFA) were thoroughly mixed in different ratios, pressed in a mold and further sintered. The polishing technique with Yttria-Stabilized Zirconia (YSZ) powder has been developed to decrease the surface roughness of Ni-based anode in order to deposit a crack-free electrolyte layer. The 3 μm YSZ thin-film electrolyte was deposited by the pulsed laser deposition technique on the surface of the anode. Morphological and elemental analyses of the samples were characterized by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyses. X-ray diffraction was used for phase analysis and structural characterization. The specific surface areas of the resulting anodes were calculated from their isotherms of N2 adsorption and desorption using the Sorbtometer and calculated by Brunauer Emmett-Teller (BET) method. As a result, the highest mechanical strength and specific surface area (15.42 m2g-1) possessed a sample with the content of PFA equal to 40%, while its ionic conductivity at 800 °C reached 6. 4∙10-2 S/cm.

This work helps address recent calls for systematic water quality assessment in Central Asia and considers how nutrient and salinity sources, and transport, affect water quality along the continuum from the cryosphere to the lowland plains. Spatial and, for the first time, temporal variations in stream water pH, temperature, electrical conductivity, and nitrate and phosphate concentrations are presented for four catchments (485-13,500 km 2 ), all with glaciers and major urban areas. The catchments studied were: Kaskelen (Kazakhstan), Ala-Archa (Kyrgyzstan), Chirchik (Uzbekistan) and the Kofarnihon (Tajikistan). Measurements were made in cryosphere, stream water, groundwater, reservoir and lake samples over a 22-month period at fortnightly intervals from 35 sites. The results highlight that glacier, permafrost and rock glacier outflows were primary and secondary nitrate sources (>1 mg N L -1 ) to the headwaters, and there were major increases in salinity and nitrate concentrations where rivers receive inputs from agriculture and settlements. Overall, the water quality complied with national and World Health Organization standards, however there were pollution hot-spots with shallow urban groundwaters contaminated with nitrate (>11 mg N L -1 ) and stream electrical conductivity above 800 μS cm -1 in some agricultural areas indicative of high salinity. Phosphate concentrations were generally low (<0.06 mg P L -1 ) throughout the catchments, though elevated (>0.2 mg P L -1 ) in urban areas due to effluent contamination. A melt water dilution effect along the main river channels was discernible, in the electrical conductivity and nitrate concentration seasonal dynamics, 100 s of km from the headwaters. Thus, the input of relatively clean water from the cryosphere is an important regulator of main channel water quality in the urban and farmed lowland plains adjacent to the Tien Shan and Pamir. Improved sewage treatment is needed in urban areas., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Andrew J Wade reports financial support and article publishing charges were provided by UK Research and Innovation. Maria Shahgedanova reports financial support and article publishing charges were provided by UK Research and Innovation. Andrew J Wade reports a relationship with UK Research and Innovation that includes: funding grants. Maria Shahgedanova reports a relationship with UK Research and Innovation that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)