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

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

Effect of the Polarizability of Organic Compounds on Isotherms of Sorption of Their Vapors with Solid tert-Butylcalix[4]arene

The stoichiometry and free energy of formation of saturated solid host-guest complexes were determined from the sorption isotherms of the vapors of organic compounds of various classes with solid tert-butylcalix[4]arene and from their limiting activity coefficients in toluene at 298 K. The contribution of the supramolecular effect to the free energy of formation of these complexes was estimated. The complexation stoichiometry and the observed supramolecular effect decrease with increasing molar refraction of the guest compound. The complexation stoihiometry is a step function of the molar refraction of the guest molecule

Estimation of the free energy of the supramolecular effect on host-guest complex formation between solid tert-butylcalix[4]arene and vapors of organic compounds

The free energy of the supramolecular effect was estimated by the difference of the free energy of the solid host-guest complex formation between the vapor guest and the solid tert-butylcalix[4]arene (1) and the free energy of the guest solvation in toluene. These thermodynamic parameters were obtained from the vapor sorption isotherms of the guests with various molecular structure by solid 1 and limiting activity coefficients of the guests in toluene determined by headspace gas chromatographic analysis. The supramolecular effect was found to decrease slightly with the increase of the guest molecular size

Организация городской полиции по «Уставу благочиния или полицейскому» 1782 г.

УДК 340The subject. The subject of analysis in the article is the organization of the city police of the Russian Empire under the Charter of the Deanery 1782. Special attention is given to the structure and legal issues of the activities of local government and its interaction with the local administrative authorities.The purpose. The growing interest in the history of local government connects not only with the aspiration of historians to look more deeply into the past but also with practical needs. Researching of the forgotten traditions of public administration allows to take greater account of historical experience that has been accumulated over the centuries as well as use it in legislation and law enforcement. We also need to take a look at already known facts and events in the light of today's realities.Methodology. Theoretical and methodological basis of the research are such principles of historical knowledge as objectivity, historicism, determinism, alternativeness and social ap-proach which are assuming an unbiased approach to the analysis of the researched problems, as well as a critical attitude to sources.Results, scope of application. The article describes the process of codification in the administrative legislation of the Russian Empire and also organization of local governance in the Russian Empire according with Charter of the Deanery. The basic aspects police activities are also characterized. This approach may overcome the old myths and misconceptions in the sphere of police organization and also prevent the birth of new ones.Conclusions. This act created the system of local police management which was centralized by establishing of the police bodies with number of state employees, specified in the law. Such institutes became both representatives of the sovereign power in the provinces and guides of its policies until reforms of the 60s and 70s of the 19 century.УДК 340В статье анализируется кодификация полицейского законодательства, а также организация местного управления Российской империи последней четверти XVIII в. согласно «Уставу благочиния или полицейскому» 1782 г. Теретико-методологической основой исследования являются принципы исторического познания – объективность, историзм, детерминизм, альтернативность и социальный подход. Особое внимание уделяется структуре и организационно-правовым вопросам деятельности местного управления, его взаимодействию с местными административно-полицейскими органами. Характеризуются основные аспекты деятельности полиции. Авторы приходят к выводу что Устав благочиния оказался устойчивым законодательным актом. Органы и институты, созданные Екатериной II, стали на долгие годы, вплоть до реформ 1860–1870 гг., не только представителями верховной власти на местах, но и прямыми проводниками ее политики

Satellite measurement based estimates of decadal changes in European nitrogen oxides emissions

Long-term satellite measurements of nitrogen dioxide in the troposphere are used in combination with a continental scale air quality model in order to verify and improve available estimates of multi-annual changes of emissions of nitrogen oxides (NO<sub>x</sub>) in Europe and the Mediterranean area between 1996 and 2005. As a result, a measurement-based data set of NO<sub>x</sub> emissions on a 1° by 1° grid and averaged over summer months is elaborated. <br><br> The results are compared with emission data based on the EMEP emission inventory. Our data are in agreement with the EMEP estimates suggesting a general decline in the level of NO<sub>x</sub> emissions in Western and Central European countries (France, Germany, Great Britain and Poland). Over Southern Europe and for shipping emissions, neutral to positive trends are found both for the inverted and bottom-up emissions. In contrast, considerable differences between both data sets are found in some other countries. In particular, significant negative trends instead of the positive ones in the "bottom-up" inventory are found for the Balkan countries, Russia and Turkey. The NO<sub>x</sub> emission trends derived from satellite measurements demonstrate larger spatial heterogeneity than those calculated with the EMEP data, especially in Russia and Ukraine. <br><br> The obtained estimates of the decadal trends in NO<sub>x</sub> emissions for Great Britain are found to be consistent with independent data from the U.K. Automatic Urban and Rural Network (AURN). It is also found that using our emission estimates yields better agreement of model calculations with near-surface ozone measurements of the European EMEP network

Influence of the guest molecular size on the thermodynamic parameters of host-guest complexes between solid tert-butylcalix[4]arene and vapours of organic compounds

The shape of guest molecules has a significantly greater influence on the free energy of supramolecular effect in the formation of solid complexes of tert-butylcalix[4]arene than on their stoichiometry

Shock-induced structures in copper

Shock loading of M3 copper within strain rate range of 5·10 6-5,7·10 6 s -1 reveals a nucleation of structural objects of 5-30 µm in diameter, which present the three dimensional frameworks composed from shear bands of 50-200 nm spacing. The structures are shown to be nucleated by means of interference of longitudinal and periphery release waves. Transition of the material into structure unstable state responsible for the shear banding happens when rate of change of the velocity variance at the mesoscale becomes higher than the rate of change of the mean particle velocity. The sites of nucleation of 3D-structures are speculated to be the staking faults generated under action of chaotic velocity pulsations relevant to dynamic deformation. The physical model for formation of 3D-structures takes into account the intersection of the partial dislocations and Lomer - Cottrell barriers

Nonlinear structure - Affinity relationships for vapor guest inclusion by solid calixarenes

The structure-affinity relationships were studied for the guest inclusion parameters of solid tert-butylthiacalix-[4]arene (1) and tert-butylcalix[4]arene (2). The inclusion stoichiometry and inclusion free energy were calculated by the sorption isotherms obtained for guest vapor-solid host systems by the static method of headspace gas chromatographic analysis at 298 K. The obtained sorption isotherms have an inclusion threshold for guest thermodynamic activity corresponding to the phase transition between the initial host phase and the phase of inclusion compound. Unlike tert-butylcalix[4]arene, its thia analogue having a larger molecular bowl is able to bind only initial members of each studied homological series. All inclusion compounds of 1 formed upon host saturation by guest vapors have the same 1:1 stoichiometry, while for 2 the inclusion stoichiometry depends on the guest molecular size. A linear correlation between the inclusion free energy (standard state: infinitely dilute guest solution in toluene) and the guest size parameter (molar refraction) was observed for 1: ΔGtrans (kJ mol-1) = -12.24 + 0.568MRD (n = 7, r = 0.972, RSD = 0.6). This correlation is regarded as a part of the V-like structure-affinity relationship with a minimum for a guest that is complementary to the host cavity