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The paper deals with the possibility of constructing mathematical models of the dependence of mechanical properties of silicon- manganese steels designed for ESW, which have high brittle fracture resistance in the HAZ, as well as of the overheated zone, on chemical composition. Data on mechanical properties of these steels were obtained as a result of studying the influence of additional alloying (microalloying) of silicon-manganese steel by manganese, chromium, vanadium, boron, cerium and zirconium on overheating resistance at electroslag welding. The method of multiple linear regression was used for construction of mathematical models. Mathematical models were constructed for the following set of base metal mechanical properties: impact toughness for temperatures of (+20, –40, –60, –70 °С), yield limit, ultimate strength, relative elongation and reduction in area. For overheated zone at electroslag welding mathematical models were constructed for impact toughness (KCU and KCV) for temperatures of +20, –60, –70 °С. Initial validation of the constructed models was performed. 9 Ref., 12 Tabl., 2 Fig. [ABSTRACT FROM AUTHOR]

It was found that in the second half of the XX century, effective measures of different directions, which were worked out by scientists, played an important role in the formation and development of scientific foundations for the conservation and efficient use of water resources in the Ukraine. It has been found that scientists have developed effective measures for irrigation and development of irrigated lands of the South of the Ukraine, drainage and agricultural use of swamps and wetlands of the Polesie and the Forest-Steppe of the Ukraine. It is determined that scientists have improved the structures and methods of calculating hydraulic structures for agricultural purposes and reclamation machines. It has been found that much attention has been paid by scientists to the establishment of optimal methods and measures for efficient agricultural water supply. [ABSTRACT FROM AUTHOR]

It is established that in the 1990s, highly effective measures worked out by scientists in different directions played an important role in the development of scientific support for water regulation in Ukraine. It is determined that the scientists have developed technological equipment and equipment for sowing crops and fertilizing with irrigation water. The efficiency of the creation of irrigation systems and new generation irrigation systems, environmentally sound reclamation systems and technologies has been determined. Improvements in technologies of application of local fertilizers and means of mechanization of their production and application have been established. It has been found that the scientists attach great importance to the development of a rational structure of acreage and crop rotation, a system of cultivation and fertilization, a complex of agricultural and ameliorative measures to prevent the degradation of irrigated lands. [ABSTRACT FROM AUTHOR]