Methodological, organizational, legal, political and other aspects of ensuring the stability of regions and territorial communities have been studied. The best world practices in this field are ...analyzed on the examples of the formation and functioning of the security districts of the Netherlands and local sustainability forums of Great Britain. Problems and prospects of ensuring the stability of regions and territorial communities in Ukraine are identified. Recommendations for the formation of a comprehensive model of interagency cooperation and coordination of activities in the field of national security and sustainability at the regional and local levels in Ukraine are proposed. Designed for experts, scientists, specialists in the field of national security, subjects of power, representatives of public organizations and individuals, all who are interested in the problems of building national stability. The publication can also be useful in the development and adoption of regulations governing legal relations in this area.
The paper is devoted to the problem of effective query execution in cluster-based systems. An original approach to data placement and replication on the nodes of a cluster system is presented. Based ...on this approach, a load balancing method for parallel query processing is developed. A method for parallel query execution in cluster systems based on the load balancing method is suggested. Results of computational experiments are presented, and analysis of efficiency of the proposed approaches is performed.
Over the recent years, an increasing attention has been paid in the Russian healthcare to the concept of a‘fast-track surgery’ also known as ‘enhanced recovery after surgery (ERAS)’. This article ...presents the advantage of inhalation anesthetic agents from the perspective of the ERAS concept. A special attention is paid to drugs belonging to halogen-containing inhalation anesthetic class (Sevoflurane and Desflurane). It is emphasized that, despite a number of differences in the clinical effect of these anesthetics, they are drugs of choice in the fast-track surgery.
Genes of adenine-specific DNA-methyltransferase M.BspLU11IIIa and cytosine-specific DNA-methyltransferase M.BspLU11IIIb of the type IIG BspLU11III restriction-modification system from the ...thermophilic strain Bacillus sp. LU11 were expressed in E. coli. They contain a large number of codons that are rare in E. coli and are characterized by equal values of codon adaptation index (CAI) and expression level measure (E(g)). Rare codons are either diffused (M.BspLU11IIIa) or located in clusters (M.BspLU11IIIb). The expression level of the cytosine-specific DNA-methyltransferase was increased by a factor of 7.3 and that of adenine-specific DNA only by a factor of 1.25 after introduction of the plasmid pRARE supplying tRNA genes for six rare codons in E. coli. It can be assumed that the plasmid supplying minor tRNAs can strongly increase the expression level of only genes with cluster distribution of rare codons. Using heparin-Sepharose and phosphocellulose chromatography and gel filtration on Sephadex G-75 both DNA-methyltransferases were isolated as electrophoretically homogeneous proteins (according to the results of SDS-PAGE).
An analysis is made of the effect of the carbon content of low-alloy steels on the damage done to slabs and rolled plates of those steels by surface defects. The effect of carbon content on the ...formation of cracks of different morphology is evaluated for the conditions that exist at the Azovstal' Metallurgical Combine.
As is known, axial segregation in continuous-cast semifinished products has a significant effect on the quality of the final metal product - plates and slabs in particular. Moreover, this effect ...becomes greater with a decrease in the reduction factor. For example, for slabs with a reduction factor less than 3-4, axial segregation leads to a decrease in mechanical properties in the Z-direction and - in certain cases - to the formation of axial cracks and the rejection of products based on defects detected during ultrasonic inspection. In connection with the increasingly stringent requirements being imposed on the quality of metal products, the combine Azovstal' has conducted studies to improve the technology needed to produce continuous-cast semifinished products for slabs thicker than 100 mm. It is necessary to significantly alleviate or completely eliminate chemical and structural nonuniformity through the thickness of the slab and to eliminate discontinuities and porosity in its axial region in order to ensure uniformity of the mechanical properties in the Z-direction. To achieve these goals, the combine has proposed using a continuous-casting technology that employs large expendable cooling devices. The method attempts to improve crystalline structure and reduce axial segregation inside the liquid pool in the continuous-cast slabs through the use of a special unit that allows the insertion of a thin (1.2-1.6 mm thick) steel strip. Heating and melting of the strip eliminates overheating of the steel being poured into the mold and improves the conditions for formation of the zone occupied by equilibrium crystals in the central region of the slabs. We tested different strips to determine the optimum chemical composition of the strip in the case of casting complex-alloyed steel.
The content of nonmetallic inclusions in steel is one of the primary indicators of the quality of the finished product. Customers' requirements on the overall quality of steel and on its nonmetallic ...inclusion content in particular have become more stringent. For example, products must conform to class 2-3 under standard SEL072, class 0-1 under standard GOST 22727, and class A under standard EN 160-85. To improve the quality of its flat-rolled products and retain its market reputation for high-quality steel alloyed with niobium, vanadium, chromium, nickel, molybdenum, and boron in different combinations, as well as for products destined for the domestic market (skelp for high-pressure gas-line pipe, plates and slabs for deep-sea drilling platforms, structural and bridge steel, ship plate, and high-strength boiler steel), the combine has had its specialists devise an integrated technology for obtaining continuous-cast semifinished products that keeps nonmetallic inclusions to a minimum.
Modern methods of steelmaking and out-of-furnace treatments of steel have made it possible to sharply reduce its content of gases, sulfur, and phosphorus. However, there has been little study of the ...effect of small concentrations of non-ferrous metals on steel's structure and properties. Lead, tin, bismuth, antimony, zinc, and other nonferrous metals enter steel from the charge, the alloying materials, and the deoxidizers. In most cases, the concentrations of these elements are not determined and are not indicated in the elemental chemical composition of the heat. In order to determine the highest concentrations of impurities of Pb, Sb, Sn, Bi, and Zn that will not significantly affect the quality of finished products made of the different steels produced by the company Azovstal', researchers at the company's laboratory studied the effect of different concentrations of each impurity individually on the quality of an alloy based on steel S355J2G3. Each of the five trial heats was cast into four ingots having different contents of nonferrous metals. The results of the studies showed that intensive cracking, flaking, and scab formation in the experimental steel became noticeable at concentrations of Pb or Bi > = 0.0055%; Sb > = 0.0038%; Sn > = 0.0060%; Zn > = 0.018%.
Improving the quality of rolled plates is one of the main goals of the metallurgical industry. This goal can be achieved through treatment of the steel outside the furnace - especially in the pouring ...ladle or tundish - with the use of chemically active elements that will refine, inoculate, and micro-alloy the melt. Such a practice is most efficiently carried out by introducing master alloys in the form of clad powder inoculants (cored wires). These materials consist of an infinite thin-walled metal tube packed with a pressed powder of suitable chemical and granulometric composition. The use of cored wires with chemically active elements allows measured, controlled introduction of refining and alloying components with a high degree of assimilation and without adverse environmental consequences. This article examines the effect of calcium and cerium introduced into steel through cored wire on the structure of the steel in the axial segregation zone and the mechanical characteristics of the rolled product in the Z-direction. We studied series of trial heats of two steels: steel 09G2S (0.09% C; 1.48% Mn; 0.56% Si; 0.008% S; 0.017% P; 0.03% Ti; 0.043% Al; 0.01% Nb; 0.009% N; 0.02% Cu); steel St 52.3 (0.20% C; 1.38% Mn; 0.36% Si; 0.006% S; 0.013% P; 0.04% Ti; 0.035% Al; 0.03% Nb; 0.011% N; 0.03% Cu).
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