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Using a model solution, we have demonstrated the feasibility of using titanium(IV) oxyhydroxyphosphate-based ion-exchange materials for extraction of Cs+ and Sr2+ cations from multicomponent high-salt bottom residues. Conditions for the use of the ion exchangers have been optimized experimentally: liquid : solid = 50, t = 25°C. It has been shown that Cs+ is effectively extracted at pH 2, whereas Sr2+, at pH 8. The zirconium-modified sorbent has been shown to have a higher affinity for metal cations. The modified sorbent is especially selective for cesium in the acid pH region owing to the higher mobility of the protons of its hydrogen phosphate groups in comparison with the unmodified sorbent composition. [ABSTRACT FROM AUTHOR]

Background: The aim of the present study was to examine the composition and content of the polysaccharide complex and polysaccharide fractions from yellow iris (Iris pseudacorus L.) rhizomes growing in Russian Federation (Moscow region). Materials and Methods: Traditional pharmacognostic methods were used in the analysis of polysaccharides as biologically active substances. The total amount of polysaccharides was determined by a gravimetric procedure with alcohol precipitation. Fractions of polysaccharides were isolated by sequential changing of solvents. The content of monosaccharides was determined by the method of high-performance liquid chromatography with refractometric detection (HPLC-RID) after acid hydrolysis. HPLC-RID procedure was performed using Chromatograph Agilent 1260 Infinity, Sugar-Pak column (300x6.5 mm), and isocratic elution mode. Results: Polysaccharide complex was isolated, the total content of polysaccharides in the rhizomes of I. pseudacorus was determined, as well as their distribution by fractions (water-soluble polysaccharides, pectic substances, hemicellulose A, hemicellulose B), the composition of individual sugars (glucose, xylose, galactose, mannose, rhamnose, arabinose) was determined for each fraction. Conclusion: In our experiment polysaccharide complex was first identified and described in detail for I. pseudacorus grown in Moscow region. [ABSTRACT FROM AUTHOR]

Studies were carried out to reduce the leakage current of high-voltage ZnO varistor ceramics by varying Sb2O3 and NiO content in a ZnO-Bi2O3-Sb2O3-Al2O3-Co3O4-NiO. It was found that the ceramic composition (wt %): ZnO 80, Bi2O3 5.83, Sb2O3 2.62, A12O3 4.66, Co2O3 3.80, NiO 3.09, has a minimum leakage current density Iout ≤ 0.1 μA cm-2, breakdown voltage Ub = 4.1kV mm-1, nonlinearity coefficient α = 65. The resulting ceramics are promising for the production of varistors with high stability of performance. [ABSTRACT FROM AUTHOR]

This paper presents a study aimed at determining the weight ratio of oxide additives for obtaining high-voltage ceramics in the ZnO–Bi2O3–Sb2O3–Al2O3–Co3O4 system containing 90 wt % ZnO, with a leakage current density under 1 μA/cm2. The ceramic containing the oxide additives in the ratio Bi2O3 : Sb2O3 : Al2O3 : Co3O4 = 0.25 : 0.17 : 1.4 : 1.4 has a nonlinearity coefficient as high as α = 69, a leakage current density as low as Il = 0.4 μA/cm2, and a breakdown voltage Vb = 4.1 kV/mm. [ABSTRACT FROM AUTHOR]

This paper presents a study aimed at determining the weight ratio of oxide additives for obtaining high-voltage ceramics in the ZnO–Bi2O3–Sb2O3–Al2O3–Co3O4 system containing 90 wt % ZnO, with a leakage current density under 1 μA/cm2. The ceramic containing the oxide additives in the ratio Bi2O3 : Sb2O3 : Al2O3 : Co3O4 = 0.25 : 0.17 : 1.4 : 1.4 has a nonlinearity coefficient as high as α = 69, a leakage current density as low as Il = 0.4 μA/cm2, and a breakdown voltage Vb = 4.1 kV/mm. [ABSTRACT FROM AUTHOR]

This paper examines the influence of the location of settlements, railroads, and highways on the spatial structure of the Otis tarda population in the Trans-Volga region that was studied in the years 1998-2016 in a model area of 12000 km2 that is located in the southern part of the Saratov Trans-Volga region. The zone of the impact made by our estimated disturbance factor due to the movement of people and a variety of ground vehicles along various-purpose roads on the territorial distribution of bustards in autumn can be denoted as a 300-500 m width band on both sides of the transport communications. Shelterbelts that were created along transport communications render a beneficial effect on the distribution of O. tarda and reduce the influence of the disturbance factor. Furthermore, crop rotation fields with side sizes of more than 1 km can be considered a factor that compensates for the anxiety of birds. We have found that in the Saratov Trans-Volga region, because of the large size of crop rotation fields and significant development of roadside and shelter belts, no special measures are required to protect O. tarda such as restrictions on the movement of people and vehicles over the territory where this species lives. [ABSTRACT FROM AUTHOR]

The ion-plasma thermal barrier coatings deposited onto samples and blades made of intermetallic VKNA-1V and VKNA-25 alloys are tested in a laboratory. The external ceramic layer of the thermal barrier coatings (TBC) is formed by magnetron sputtering of zirconium alloy targets and has a columnar structure. The influence of NiCrAlY(Re, Ta, Hf) + AlNiY(Hf) + ZrYGdO TBC on the long-term strength at a test temperature of 1200°C and on the high-cycle fatigue at a temperature of 900°C is studied. Blades with TBC are subjected to thermal cycling tests in the temperature range 950 ↔ 400°C and 1050 ↔ 400°C during air cooling and in the range 950 ↔ 200°C during water cooling at 500 cycles. The temperature fields in the cross section of a blade airfoil during thermal cycling are calculated. The laws of formation of fracture zones and the development of thermal fatigue cracks under the conditions that are close to the operating conditions of nozzle TBC-containing blades are investigated. [ABSTRACT FROM AUTHOR]

Varistor powders were synthesized by accelerated combustion of an aqueous solution of hydrated zinc, bismuth, aluminum, cobalt, and nickel nitrates, antimony tartrate, and sugar at 500°С with isothermal heating for 10 min, followed by grinding and calcination at 700°С for 1 h. The varistor powders obtained have high specific surface area and allow preparation of a ceramic with high values of the breakdown voltage and nonlinearity coefficients and with low leakage current density. The ceramic of the optimum composition (wt %), ZnO 75, BiO 7.36, SbO 5.1, AlO 7.19, CoO 4.8, and NiO 0.61, sintered at 975°С for 4 h, has U = 4.2 kB mm, α = 54, and I = 0.2 μA cm. [ABSTRACT FROM AUTHOR]