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The present work was aimed at the investigation of effect of High Energy Ball Milling (HEBM) time on the sintering kinetics, structure, and properties of heavy tungsten alloy (HTA) W-7%Ni-3%Fe. The HTA samples were obtained from the nanopowders (20-80 nm) by conventional liquid phase sintering (LPS) in hydrogen and by Spark Plasma Sintering (SPS) in vacuum. The HTA density was shown to depend on the HEBM time non-monotonously that originates from the formation of non-equilibrium solid solutions in the W-Ni-Fe systems during HEBM. The SPS kinetics of the HTA nanopowders was shown to have a two-stage character, the intensity of which depends on the Coble diffusion creep rate and on the intensity of diffusion of the tungsten atoms in the crystal lattice of the -phase. The kinetics of sintering of the initial submicron powders have a single-stage character originating from the intensity of the grain boundary diffusion in the -phase. The dependencies of the hardness and of the yield strength on the grain sizes were found to obey the Hall-Petch relation. The hardness, strength, and dynamic strength in the compression tests of the fine-grained tungsten alloys obtained by SPS and LPS were studied.

В статье раскрыты основные методики, используемые при травмах голеностопного сустава, а также выявлены и раскрыты физические упражнения, направленные на укрепление мышц стабилизаторов голеностопного сустава для более быстрого восстановления.

The reaction of N-amino-1,10-phenanthrolinium mesitylenesulfonate with acceptor-substituted alkenes in the K2CO3–DMSO system gave 3- and 2,3-substituted pyrazolo[1,5-a][1,10]phenanthrolines. A wide range of alkenes enter into this reaction; however, in the case of nitro derivatives, complex mixtures of products were formed.

The dynamic strength of heavy 90W—7Ni—3Fe alloy (wt %) was studied on two types of specimens: formed from submicron powder by spark plasma sintering (SPS) and from coarse-grained powder with a particle size of ≈20 µm by standard liquid phase sintering (LPS). Mhe study shows that the dynamic strength of the LPS and SPS specimens ranges up to 2750 and 3150 MPa, respectively, and that the SPS projectiles at an impact velocity of 1200 m/s penetrate 60% deeper into a steel target than the LPS projectiles. The difference in the penetration depth results from different penetration mechanisms: piercing for the coarse-grained material and cratering for the fine-grained one.

The problem of cyclic organization of geological environment in the Pleistocene is specified based on of materials on absolute chronology of marine and intracontinental sediments of North and Central Asia and North America. New data on absolute chronology of fluvial transgressive-regressive cycles of the Pleistocene in comparison with the known solar climate scale of M. Milankovich’s are given. It is established that the two most ancient dates of the terrace sediments of the Lena River (234 and 182 thousand years ago) and the Vilyuy River (300 and 176 thousand years ago), as well as three groups of dates of younger Late Pleistocene and Holocene fluvial formations in the valley of the Lena River, Rocky Mountains and in the Primorsky Lowland of the Laptev Sea (36 - 42.8; 27-29 and 8-10 thousand years ago) correlate with the M. Milankovic’s curve, describing the variability of the Earth’s solar climate with the period of about 41000 years. The oldest dates - 300 and 234 thousand years ago, and the date series in the chronological range 27-29 thousand years ago (five dates) coincide with the cold extremums of the M. Milankovic scale. Dates of 182 and 176 thousand years ago, as well as series of the dates in the range 36-42 thousand years ago (four dates) and 8-10 thousand years ago (3 dates) tend to warm extremums of the same scale.

Results of experimental studies and numerical modeling of high strain rate of aluminum alloy AK4-1 (analog AU2GN) have been presented. Using Split Hopkinson Pressure Bar (SHPB) method stress-strain curves under compression and tension have been obtained. On the basement of these results appropriate parameters of some constitutive equations have been calculated. Strength and deformation material failure properties, dynamic crack resistance, dynamic friction factor for material pair aluminum-titanium have been obtained by carrying out of modificated SHPB tests. A verification of the constitutive equations has been realized by dynamic indentation method and modified Taylor test.

The results of investigation of dynamic compressibility of clay and loam at strain rate 10(3) s(-1) and higher are presented. At strain rate similar to 10(3) s(-1) the experiments were carried out by using modification of Split Hopkinson Pressure Bar (SHPB), plate impact experiment was used at strain rate similar to 10(4) s(-1) and higher. Shock adiabats were determined by reflection method. As the result of the experiments dynamic compressibility curves, hydrostatic curves and dependence of shear strength from pressure were obtained at uniaxial strain conditions. The joint use of these complementary methods has allowed to extent a range of loading conditions. The results obtained can be useful for formulation of equations of state for clay and loam.

It is known that experiments with intensive dynamic influences and high-speed deformation of specimens under tension are important in the analysis of deformations and strength of structures and their elements. The most reasonable and widely used method for obtaining dynamic stressstrain curves, characteristics of ultimate strength and deformations is the modified Kolsky method. It should be noted a small number of publications on the analysis of the influence of fillets and the length of the working part of the specimen on the most important mechanical characteristics obtained by this method. This work is aimed at increasing knowledge in this area. By numerical and experimental analysis it was established that when the working part of the specimen has a length of 5 mm, then the uniformity and one-dimensionality of the stressed state are seriously violated. When choosing the length of the specimen in the Kolsky method, there are important limitations: the length of the specimen must be much smaller than the length of the loading pulse. Therefore, in this study, two specimen lengths of 10 and 15 mm were analyzed. In this paper, we give experimental and calculated diagrams and their comparison with each other. It was shown, that for the above-mentioned lengths, the homogeneity and one-dimensionality of the stressed state is substantially improved.

The combined experimental and theoretical approach was applied to the study of high-speed deformation and fracture of the 1810 stainless steel. The material tests were performed using a split Hopkinson pressure bar to determine dynamic stress-strain curves, strain rate histories, plastic properties and fracture in the strain rate range of 102 ÷ 104 s-1. A scheme has been realized for obtaining a direct tensile load in the SHPB, using a tubular striker and a gas gun of a simple design. The parameters of the Johnson-Cook material model were identified using the experimental results obtained. Using a series of verification experiments under various types of stress-strain state, the degree of reliability of the identified mathematical model of the behavior of the material studied was determined.

A description of experimental complexes, methodological and hardware means for determining the mechanical properties of materials under high-speed deformation and fracture is given in the report. Determination of mechanical properties in the strain rate range 5•102÷103 s-1 is the first direction of work in the laboratory of “Dynamic Materials Testing”. These tests are done using automated complexes based on the Kolsky method and its modifications for compression, tension and shearing. It is also possible to determine the fracture toughness, the characteristics of dynamic crack resistance, as well as to obtain stressstrain curves of low-density materials under uniaxial strain. Original gas guns with a caliber of 10, 20 and 57 mm are used for creation a dynamic load. The study of the behavior of materials at strain rates of 105 s-1 and higher is the second direction of work. In this case, the methods of a planewave shock experiment based on gas guns of 57 and 85 mm caliber are used. Manganine and dielectric pressure sensors, as well as laser interferometry are used for measuring the parameters of elastoplastic waves and for determining such important characteristics as impact compressibility, Hugoniot yield strength, spall strength.

A study of the strength and deformation properties of freshwater ice under compression, tension and shear in a wide range of strain rates (10−4 − 3 ⋅ 103 s−1 ) and temperatures of − 5∘ C, − 20∘ C, − 40∘ C and − 60∘ C was performed. Static stress-strain curves of ice under compression were obtained on which the identified strength properties of ice as well as compressive modulus. To determine the mechanical properties of ice at high-speed loading the Kolsky method was used with various embodiments of split Hopkinson bar. The deformation curves were obtained at various loading conditions. Thereon breaking points were defined as well as their dependence on the strain rate and temperature. Also static and dynamic strength properties of ice at splitting and circular shear were defined. Increase in the dynamic strength properties upon the static ones for all loading conditions was marked.

The functioning and development of the system of education as a social institution is characterized by specific internal contradictions, which are reflected in scientific cognition in the form of a set of theoretical problems. Along with pedagogical, psychological, economic, and other problems, properly sociological problems can also be discerned. The basic characteristic of these latter is that they reflect contradictory interactions between the system of education and society as a global-social system. From this it follows that this interaction is the object of the sociology of education in the broadest sense.

The project to erect a hydroelectric station cascade on the Katun River (Gorno-Altai Autonomous Oblast) has provoked extremely heated discussions: proponents of its realization point to the shortage of energy in the region and the impossibility (for a number of reasons) of resolving the energy problems in any other way; opponents speak of the possible unfavorable (environmental, as a rule) consequences of the construction. Since we are not specialists in the realm of economics or the environment, we shall refrain from expressing our views on this subject and shall direct readers' attention to an aspect of the problem that is discussed in the press much less frequently—the possible ethnosocial consequences of the Katun project's implementation.

Arterial hypertension accompanied by prostate benign hyperplasia is very important not medical but social problem in elderly people. The clinical and neuroimmunoendocrine status of elderly patients with arterial hypertension accompanied by prostate benign hyperplasia treated by alpha1-blocker doxasosine is described in the article. Intercellular interactions were examined for tumor necrosis factor alpha, proinflammative interleukine-6, soluble intersellular molecule of adhesion. The positive role of doxasosine is demonstrated.

A new simple method has been developed for determining the impact adiabate of a soft soil from the results of inversed tests using a pressure bar with a flat edge.

The results of dynamic tests of two refractory materials based on zirconium dioxide: three types of ceramics and barium-aluminate concrete. The ceramic specimens had various initial density and porosity and also differed by technology of manufacturing. Compression tests were carried out using the Kolsky technique and its updating - specimen in a rigid jacket. The dynamic stress-strain curves were obtained. The strong influence of sample's initial grain composition, mode of stressed-strained state and technologies of manufacturing of specimens onto ceramics mechanical properties is marked. In the event of a serious accident in a nuclear reactor with its core melting, it becomes crucial to prevent the propagation of the resulting radioactive flux into the en- vironment. The problem of confining the melting core is vital for all the countries using nuclear power plant. A corium trap material is anticipated to undergo an influence of various factors, such as mechanic and thermal shocks resulting after falling the melt and the structural elements into the trap, a vapor explosion resulting from the contact of the melt with water, chemical interaction with corium, and a radiation effect. The anticipated high temperature of corium (2800-3000K) and its chemical activity in oxidizing conditions considerably reduce the choice of materials that could be used for the trap. The currently developed corium trap based on using the highly refractory dioxide zirconium concrete has to increase the life of a protecting trap by two orders of mag- nitude as compared to the construction concrete. However, use of the cements with the melting temperatures of 2300 K and lower in the above concrete reduces the merits of the refractory component - zirconium dioxide. The dioxide zirconium-based sintered ceramics is free from the above drawbacks. To assess the potential of using dioxide zirconium ceramics, comparative studies of dynamic strength of the ceramics and of some highly refractory concretes under high-velocity loading are to be conducted. The aim of the paper is to analyze experimentally the influence of the loading rate on the strength properties of dioxide- zirconium ceramics and concrete based on zirconium aluminate.

Research into sociological problems pertaining to the intelligentsia, which is an inseparable part of the new historical community the Soviet people, requires theoretical treatment of a number of initial concepts. One of them is "the social facies [sotsial'nyi oblik] of the intelligentsia."

Effective control of the development of the social structure of socialist society with the aid of the education system is today an urgent problem. The education system has the potential of reducing differences among classes and social groups and of eliminating social distinctions between town and countryside and between people engaged in physical or mental labor.

Effective control of the development of the social structure in socialist society, aided by the educational system, is a very urgent problem under present conditions. The system of education has the potential to bring different classes and social groups closer together and to eliminate social differences between town and country, and between manual and nonmanual workers.

Improvement in the public education and occupational training of young people are an integral part of the optimization of developed socialist society. The shift to intensive economic development, the actualizaton of a broadscale, integral socioeconomic program, the ongoing expansion and reinforcement of socialist democracy, the practical construction, in the main and basically, of a classless social structure, and the shaping of the new man elicit an imperative demand for far-reaching change within the educational system. At the Twenty-sixth CPSU Congress, a definition for development in our society over the current decade was followed by a call "to enhance the operational efficiency of all the units and forms of education and cadre training." [1]