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

Pannexin 1 facilitates arterial relaxation via an endothelium-derived hyperpolarization mechanism

AbstractPannexin 1 (Panx1) is involved in endothelium-dependent vasodilation in large arteries, but the exact mechanistic role remains poorly understood. We hypothesized that Panx1 facilitates large vessel relaxations regulating endothelium-derived hyperpolarization (EDH)-like mechanisms. The EDH-like component of acetylcholine-induced relaxation of saphenous arteries studied in isometric myograph after inhibition of NO-synthase and cyclooxygenase was significantly impaired in mice with genetically ablated Panx1 (KO) relative to that in the wild type (WT) mice. Application of P1-receptor antagonist and apyrase significantly reduced this component in WT, but not in KO mice, indicating participation of ATP released via Panx1 in the EDH-like relaxation

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

The lichens of forest rocky communities of the hill Muroigora (Arkhangelsk Region, Northwest Russia)

The present study reports 188 species and 2 subspecies of lichens and allied fungi from forest rocky communities of the hill Muroigora situated in the Arkhangelsk part of the National park “Vodlozersky” (Arkhangelsk Region, NW Russia). Lepraria ecorticata is new to Russia, and 13 more species are new for the mainland area of the Arkhangelsk Region: Arthonia mediella, Arthonia vinosa, Bacidia igniarii, Bryoria vrangiana, Chaenothecopsis pusiola, Cladonia caespiticia, Lecidea plana, Lepraria borealis, Micarea misella, Pertusaria pustulata, Schaereria cinereorufa, Xanthoparmelia pulla and Xylographa trunciseda. Two lichen species, Bryoria fremontii and Lobaria pulmonaria, are in the Red Data Books of the Arkhangelsk Region and Russian Federation. A total of 89 species are reported as new for the Vodlozersky National Park.

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

ANALYSIS OF THE DIGITAL TRANSFORMATION OF GENERAL EDUCATION

Digital transformation of the society, boosted by the COVID-19 pandemic, has determined new processes in the socio-economic sphere. Foreign and domestic researchers are unanimous in their opinion that digitalization is the main trend of global development, and the need for digital transformation of education is preconditioned by organizational, technological, managerial, economic, and other changes taking place in various spheres of society, economy and production. Object of the study: the digital transformation process. Subject: general education. Goal: to identify the essence and characteristics of the implementation of digital transformation processes in general education. Objectives: to analyze the essence and semantic understanding of the "digital transformation" category; to describe the types and structure of the main processes of digital transformation in general education. Methods: methodological approaches: systemic approach; research methods: theoretical (analysis of information sources; comparative study; content analysis; generalization, systematization). Conclusions: there is no unity in the scientific attribution of the concepts of "digitalization of education", "digital transformation of education"; analysis of the prospects of digital transformation of general education indicates that its main positive effects may be as follows: ensuring equality of educational opportunities and continuity of education; updating the goals and content of education; optimizing forms, methods, teaching and methodological support of the educational process and the students’ learning and cognitive activities; creating conditions for personalized learning; increasing the effectiveness of quality control and monitoring; reducing the amount of routine work for management and teaching staff, etc.; based on the analysis of scientific research, the problem of information security of electronic educational resources used in general education has been identified; an analysis of the current situation on the software market is presented, and general recommendations on the protection of data recorded in electronic educational resources are give

Evaluation of cardioprotective effects of the incritinmimetics exenatideand vildagliptin in the experiment

The results of experimental and clinical trials make it clear that incretin mimetics possess pleiotropic effects and demonstrate the value in terms of assessment of their potential opportunities as cardioprotectors. Goals: To study the cardioprotective effects of exenatide and vildagliptin on the model of doxorubicin-induced cardiomyopath

PROGNOSTIC ROLE OF EEG INDICATORS FOR CHANGES IN COGNITIVE PERFORMANCE IN PATIENTS IN THE EARLY AND LONG-TERM POSTOPERATIVE PERIODS OF CORONARY ARTERY BYPASS GRAFTING

Aim. To study the prognostic role of background EEG activity indicators recorded in patients in the preoperative period of coronary artery bypass grafting (CABG) for the development of cognitive impairment in the early and late postoperative periods.Methods. A total of 85 patients with coronary artery disease (CAD) who underwent CABG were included in the study. Before CABG (3-5 days) all neuropsychological testing and EEG studies were performed, at the 7-10th days and 1 year after CABG only neuropsychological testing. EEG predictors of early (n = 85) and long-term (n = 65) postoperative cognitive dysfunction were detected using the method of multiple linear regression.Results. EEG predictors of deterioration of cognitive status in the early postoperative period of CABG were basic higher values of theta-rhythm power in the posterior regions of the cortex of both hemispheres with closed and open eyes. Whereas higher preoperative parameters of beta2-rhythm biopotentials in the left frontal areas with eyes open and lower alpha-rhythm power in the left occipital parts of the cerebral cortex with eyes closed were associated with long-term postoperative cognitive dysfunction.Conclusion. associations of preoperative eeg indicators with deteriorations of cognitive status in the early and longterm postoperative periods of cabg were revealed. Aim. To study the prognostic role of background EEG activity indicators recorded in patients in the preoperative period of coronary artery bypass grafting (CABG) for the development of cognitive impairment in the early and late postoperative periods.Methods. A total of 85 patients with coronary artery disease (CAD) who underwent CABG were included in the study. Before CABG (3-5 days) all neuropsychological testing and EEG studies were performed, at the 7-10th days and 1 year after CABG only neuropsychological testing. EEG predictors of early (n = 85) and long-term (n = 65) postoperative cognitive dysfunction were detected using the method of multiple linear regression.Results. EEG predictors of deterioration of cognitive status in the early postoperative period of CABG were basic higher values of theta-rhythm power in the posterior regions of the cortex of both hemispheres with closed and open eyes. Whereas higher preoperative parameters of beta2-rhythm biopotentials in the left frontal areas with eyes open and lower alpha-rhythm power in the left occipital parts of the cerebral cortex with eyes closed were associated with long-term postoperative cognitive dysfunction. Conclusion. associations of preoperative eeg indicators with deteriorations of cognitive status in the early and longterm postoperative periods of cabg were revealed

Russian and Foreign Experience of Placement for Orphans

Children are the main value of the country, they need care and special attention. The government is obliged to ensure the implementation of children's rights to upbringing, education and development. The family education of children is the priority form. However, there is a problem of orphanage and social orphanage, children left without parental care. There are various forms of placement for orphans. The family form of the placement, foster families, are priority in the world