Effect of anion doping on mobility of ionic charge carriers in solid solutions based on Ba2In2O5

In the work, mobilities of oxygen and protons are determined for F --substituted solid solutions based on brownmillerite Ba 2In2O5 and their concentration dependences are analyzed. It is found that small additives of the more mobile anion (F - ions) promote an increase in oxygen mobility as a result of additional effects of repulsion of ions of different nature in the anion sublattice. Mobility of oxygen at high fluoride concentrations decreases due to the overlapping of migration paths of diffusion, as both anions, fluoride ions and oxygen ions, move via oxygen vacancies. Concentration dependences of mobility of proton carriers have a similar character, which is related to the effect of the oxygen sublattice. The anion doping method used in the work can be recommended as the general method for improvement of the transport characteristics of oxygen-ionic and protonic conductors with a perovskite-like structure. © 2013 Pleiades Publishing, Ltd

The Role of Plastic Flow in Processes of High-speed Sintering of Ceramic Materials under Pressure

A model to describe the kinetics of the compaction of conductive nitride ceramics using electropulse technologies is developed. The relationship between density and pressure is established on the basis of three components of the geometric, plastic and stressed state, which is affects the contact area between the particles. The model takes into account the change in the relative area of the interpartial contacts under the action oftwo mechanisms of mass transfer-diffusion and plastic flow. It is shown that a decrease in the particle size of the powder leads to an in-crease in the diffusion contribution and a decrease in the plastic flow, at all other conditions being equal. And for the case of nano-sized particles, diffusion mass transfer is predominant.Increasing in the heating rate leads to a decrease in the contribution of dif-fusion mass transfer at equal temperatures, as well as to an increase in the temperature of the beginning of shrinkage.The processes of plasma-plasma sintering, high-voltage electro-pulsed consolidation and hot pressing control the same mechanisms, plastic flow and diffusion mass transfer, which do not require, in the first approximation, the influence of the electric current on the properties of materials. Keywords: spark-plasma sintering, high-voltage electrodischarge consolidation, sintering kinetic

Electric properties of oxyfluorides Ba2In2O 5-0.5x F x with brownmillerite structure

Synthesis of fluoro-substituted substances based on brownmillerite Ba 2In2O5 is carried out. The width of the homogeneity region of the Ba2In2O5-0.5x F x (0 < x ≤ 0.25) solid solution was established using X-ray analysis. Measurement of temperature dependences of conductivity in atmospheres with different partial pressure of water vapor (pH2O = 3.3 and 2 Ч 103 Pa) showed an increase in conductivity at T ≤ 550 C in a humid atmosphere, which is due to appearance of proton transport. The dependence of conductivity on partial oxygen pressure (pO2 = 0.21 Ч 105 to 10-15 Pa) is studied in the temperature range of 500-1000 C; ion transport numbers are calculated. The method of polarization measurements was used to determine transport numbers of fluoride. Total conductivity is divided into ion (proton, oxygen, and fluoride ion) and electron components. Analysis of concentration dependences of conductivities showed that low concentrations of fluoride allow increasing both the total and partial conductivities (oxygen-ion and proton) and, besides, allow shifting the "order-disorder" phase transition by 100 C to the low temperature range. © 2013 Pleiades Publishing, Ltd

The American aid to the Russian reforms at the end of the twentieth century

The importance of the studied problem is caused by the USA’s leading role in the development of modern world order and the economy, its influence in the international economic organizations. The article is aimed at revealing the reasons of choosing neoliberal strategy for Russian reforms, the amount and results of the American financial and technical aid to these reforms. The leading approach of researching this problem is the complex one. It allows finding out economic, internal political, geopolitical and cultural factors which influenced the implementation and the results of the American assistance to the Russian reforms. Authors draw a conclusion about considerable influence of the USA on domestic policy of Russia in the early nineties of the XX century. The amount and the content of the American financial and technical assistance to the Russian government are analyzed. Promises of massive financial aid from the international economic organizations and the USA were realized partially and much later, than it was necessary for economic transformations. The article’s content and conclusions can be used in other scientific works on American-Russian relations history, Modern history of Russia, during elaboration the effective strategy of reforms for the countries which are in a condition of a transitional economy. © 2016 Tarasova et al

Short-term Mechanical Properties of Fe-Cr-Al-Si Alloys

The purpose of this work is to study the short-term mechanical properties of Fe-Cr-AlSi-based alloys. Within the framework of this work, alloys with a chromium content of 5 to 14 wt%, aluminum from 0 to 4 wt%, and silicon from 0 to 4 wt% are considered. The samples were tested in three different states - in the deformed state (cold rolling by 80%), and also after annealing at a temperature of 450 and 650 ∘C with a duration of 1000 h.As a result, the characteristics of the strength and plasticity of alloys in the deformed state, as well as after provoking annealing, were obtained. It is shown that embrittlement isn’t observed in the investigated composition region and annealing conditions, and the strength of the alloys is directly proportional to the sum of the alloying elements Al + Si. Keywords: cladding; VVER; tolerant fuel, ferrite steel; Corrosion-resistant steel, tensile strength, yield strengt

The Effect of Simultaneous Homo- and Heterogeneous Doping on Transport Properties of Ba2In2O5

In this article, the possibility of application of simultaneous homogeneous and heterogeneous doping has been described for the first time. The composite 0.7Ba1.95In2O4.9F0.1⋅0.3Ba2 InNbO6 has been obtained by in situ solid-state method. The scanning electron microscopy and thermogravimetry investigations have beencarried out; the electrical properties have been examined. It has been proved that simultaneous homogeneous and heterogeneous doping is a prospective method for obtaining high-conductive proton electrolytes. Keywords: brownmillerite, composite, anionic doping, fluorin

Multimedia technology in teaching of bachelors

The article discusses the application of multimedia technologies in the teaching of bachelors of the university, analyzes the specifics of using these technologies in the learning process, the need to apply modern technologies in the process of self-development and self-study of students at a universityРассматриваются вопросы применения мультимедийных технологий и особенности их использования в процессе саморазвития и самообучения бакалавро

A climatology of surface ozone in the extra tropics: cluster analysis of observations and model results

Important aspects of the seasonal variations of surface ozone are discussed. The underlying analysis is based on the long-term (1990–2004) ozone records of the Co-operative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (EMEP) and the World Data Centre of Greenhouse Gases, which provide data mostly for the Northern Hemisphere. Seasonal variations are pronounced at most of the 114 locations at all times of the day. A seasonal-diurnal variations classification using hierarchical agglomeration clustering reveals 6 distinct clusters: clean background, rural, semi-polluted non-elevated, semi-polluted semi-elevated, elevated and polar/remote marine. For the "clean background" cluster the seasonal maximum is observed in March-April, both for night and day. For those sites with a double maximum or a wide spring-summer maximum, the spring maximum appears both for day and night, while the summer maximum is more pronounced for daytime and hence can be attributed to photochemical processes. The spring maximum is more likely caused by dynamical/transport processes than by photochemistry as it is observed in spring for all times of the day. We compare the identified clusters with corresponding data from the 3-D atmospheric chemistry general circulation model ECHAM5/MESSy1 covering the period of 1998–2005. For the model output as for the measurements 6 clusters are considered. The simulation shows at most of the sites a spring seasonal maximum or a broad spring-summer maximum (with higher summer mixing ratios). For southern hemispheric and polar remote locations the seasonal maximum in the simulation is shifted to spring, while the absolute mixing ratios are in good agreement with the measurements. The seasonality in the model cluster covering background locations is characterized by a pronounced spring (April–May) maximum. For the model clusters which cover rural and semi-polluted sites the role of the photochemical production/destruction seems to be overestimated. Taking into consideration the differences in the data sampling procedure, the comparison demonstrates the ability of the model to reproduce the main regimes of surface ozone variations quite well