168 research outputs found
Effect of Structure and Texture on Failure of Pipe Steel Sheets produced by TMCP
The method of orientation microscopy (EBSD) is used to study the structure and texture of low-carbon, low-alloy pipe steel sheets processed by controlled thermomechanical processing (TMCP). The temperatures of isothermal hot rolling varied. Samples cut from sheets showed a different fracture tendency during mechanical testing. The formation of cleavages (secondary cracks) during failure of steel is related to the presence of ferrite grains with orientation {001} <110> extended in the hot rolling direction. The formation of grains is a consequence of the isothermal hot rolling below the temperature
The effect of accelerated cooling on the structure of pipe steels for thermomechanical controlled processing
Scanning electron microscopy with orientation analysis by the electron backscatter diffraction (EBSD) method is used to study microstructures and textures formed in low-carbon low-alloy pipe steel after thermomechanical controlled processing (TMCP) and subsequent quenching with cooling rates of 50 to 700 Β°/s. It has been established that, in the range of industrial rates of cooling between 50 and 350 Β°/s from austenitic regions, the Ξ³βΞ± transformation starts at temperatures of 700-670 Β°C and proceeds by the shear mechanism. As a result, a bainite structure of different dispersity with martensitic inclusions is predominantly formed. Β© 2018 Author(s)
Uranium stripping from tri-n-butyl phosphate by hydrogen peroxide solutions
The processes of uranium stripping from 30% tri-n-butyl phosphate (TBP) in "odorless" kerosene by H2O2 solutions both with and without NH4OH added were investigated in the temperature range of 20-50 C and with a volumetric ratio of 1 between the organic and aqueous phases. The uranium was selectively precipitated in the form of uranium peroxide during stripping from the organic phase by hydrogen peroxide. The stripping of uranium increased with increasing H2O2 content, increasing temperature and increasing concentration of NH3 in the range of 0-15 g/L. The use of a heated solution (40 C) that contained 4 mol H 2O2/mol U and NH3 12 g/L resulted in 99.7% of the uranium being stripped from TBP in the form of uranium peroxide. The uranium peroxide obtained by stripping is a highly pure product that exists in two different hydrated forms: UO4Π²Μβ’4H2O (92 mass %) and UO4Π²Μβ’2H2O. The mean particle diameter was 20.75 ΞΌm. The effect of hydrogen peroxide on the organic phase was studied by IR spectroscopy. No structural changes in TBP were observed after 30 cycles of extraction/stripping; thus, the use of hydrogen peroxide in this application is unrestricted. Β© 2013 Elsevier B.V
Evolution of microstructure in stainless martensitic steel for seamless tubing
Scanning electron microscopy with orientation analysis by the electron backscatter diffraction (EBSD) method is used to study microstructures and textures formed in the 0.08C-13Cr-3Ni-Mo-V-Nb steel through seamless tube production route: after hot deformation by extrusion; after quenching from various temperatures and subsequent high tempering. It is shown that the martensitic microstructure formed both after hot deformation and after quenching is characterized by the presence of deformation crystallographic texture, which is predetermined by the texture of austenite. The effect of heat treatment on texture, packet refinement, lath width, precipitation of carbides and Charpy impact energy is analyzed. Β© 2017 Author(s).The work was done using the equipment of the laboratory of Structural Methods of Analysis and Properties of materials and nanomaterials of the Collective Use Center affiliated to Ural Federal University. The study was supported by the program of increasing the competitiveness of the leading Russian universities, RF Government resolution No. 211, contract No. 02.Π03.21.0006. We are grateful to the TMK company for their support and assistance in organizing the study
SPECIES PECULIARITIES OF LIPID SPECTRA OF BLOOD IN REPRESENTATIVES OF GOBY FISH IN LAKE BAIKAL: NEW OPPORTUNITIES OF RESEARCH OF MECHANISMS OF RESISTANCE TO DYSLIPOPROTEIDEMIA AND ATHEROSCLEROSIS
Rhizobacteria Effect on Arsenic Migration and Translocation of Biogenic Elements in Plants
The study was aimed at the transformation of arsenic compounds in the rhizosphere, its accumulation in plants, P and Si translocation to plants under the influence of Bacillus megaterium var. phosphaticum, and Bacillus mucilaginosus with various forms of As compounds in the soil. The authors describe the maximum effect of Bacillus megaterium var. Phosphaticum strain on As migration, its mobilization and immobilization in the rhizosphere due to arsenic leaching from mineral and difficult-todestroy compounds and its accumulation in plants. The forms of arsenic compounds were isolated from the rhizosphere based on sequential extraction procedures. The features of the inter-element As-P interaction in plants were established. With the intense accumulation of As in the rhizosphere inoculated with rhizobacteria, the intake of phosphorus into plants was not observed, as contrary to Si. The study of As and biogenic elements behavior under the influence of rhizobacteria is of great importance in the development of ecobiotechnologies related to soil remediation and crop production
Features of shear transformation texture in seamless pipes
Microstructure and texture in seamless 0.08C-Cr-Mo-V, 0.25C-Cr-Mo-V-Nb, 0.08-13Cr-3Ni-Mo-V-Nb, and 18Cr-9Ni steel pipes are studied in the as-rolled and heat-treated states using orientation EBSD microscopy. It has been found that all types of microstructure (ferrite, martensite, and bainite) in products, both after hot rolling and after heat treatment, have well-defined axial crystallographic texture, where the direction is predominately perpendicular to the pipe surface. It is demonstrated that texture formation in heat-treated states is inherited due to the following factors important for the rules of orientation selection during the Ξ³βΞ± phase transformation: 1) occurrence of stable orientation of austenite grains resulted from straining; 2) special misorientation (boundaries) of austenite grains where transformation starts; 3) orientation relationships known for phase transformation; 4) thermal stresses in a product, formed during cooling. The latter can be considered as factor determining special texture in seamless steel pipes. Β© 2018 Author(s)
Investigation of the influence of some saliva enzymes on the biofilm forming activity and the growth kinetics of candida at various values of Ph
In the present study, yeast-like fungal strains isolated from patients were cultured under certain pH conditions, and growth dynamics were evaluated at pH 5.0 and 7.0, as well as at various concentrations of lysozyme, and the biofilm-forming activity of the strains was evaluated in parallel. The absence of a significant effect of lysozyme on the biofilm formation of C. albicans in a medium with a pH of 7.0 was shown. With decreasing pH, the biofilm-forming activity of candida decreases proportionally significantly and lysozyme under such conditions contributes to the destruction of biofilms.Π Π½Π°ΡΡΠΎΡΡΠ΅ΠΌ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠΈ Π²ΡΠ΄Π΅Π»Π΅Π½Π½ΡΠ΅ Ρ ΠΏΠ°ΡΠΈΠ΅Π½ΡΠΎΠ², ΡΡΠ°ΠΌΠΌΡ Π΄ΡΠΎΠΆΠΆΠ΅ΠΏΠΎΠ΄ΠΎΠ±Π½ΡΡ
Π³ΡΠΈΠ±ΠΊΠΎΠ² ΠΊΡΠ»ΡΡΠΈΠ²ΠΈΡΠΎΠ²Π°Π»ΠΈ Π² ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π½ΡΡ
ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΡΠ, ΠΏΡΠΈ ΡΡΠΎΠΌ ΠΎΡΠ΅Π½ΠΈΠ²Π°Π»ΠΈ Π΄ΠΈΠ½Π°ΠΌΠΈΠΊΡ ΡΠΎΡΡΠ° ΠΏΡΠΈ ΡΠ 5,0 ΠΈ 7,0, Π° ΡΠ°ΠΊΠΆΠ΅ ΠΏΡΠΈ ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ
ΠΊΠΎΠ½ΡΠ΅Π½ΡΡΠ°ΡΠΈΡΡ
Π»ΠΈΠ·ΠΎΡΠΈΠΌΠ°, ΠΏΠ°ΡΠ°Π»Π»Π΅Π»ΡΠ½ΠΎ ΠΏΡΠΎΠΈΠ²ΠΎΠ΄ΠΈΠ»ΠΈ ΠΎΡΠ΅Π½ΠΊΡ Π±ΠΈΠΎΠΏΠ»Π΅Π½ΠΊΠΎΠΎΠ±ΡΠ°Π·ΡΡΡΠ΅ΠΉ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΡΡΠ°ΠΌΠΌΠΎΠ². ΠΠΎΠΊΠ°Π·Π°Π½ΠΎ ΠΎΡΡΡΡΡΡΠ²ΠΈΠ΅ Π·Π½Π°ΡΠΈΠΌΠΎΠ³ΠΎ ΡΡΡΠ΅ΠΊΡΠ° Π»ΠΈΠ·ΠΎΡΠΈΠΌΠ° Π½Π° Π±ΠΈΠΎΠΏΠ»Π΅Π½ΠΊΠΎΠΎΠ±ΡΠ°Π·ΠΎΠ²Π°Π½ΠΈΠ΅ C. albicans Π² ΡΡΠ΅Π΄Π΅ Ρ ΡΠ 7,0. ΠΡΠΈ ΡΠ½ΠΈΠΆΠ΅Π½ΠΈΠΈ ΡΠ Π±ΠΈΠΎΠΏΠ»Π΅Π½ΠΊΠΎΠΎΠ±ΡΠ°Π·ΡΡΡΠ°Ρ Π°ΠΊΡΠΈΠ²Π½ΠΎΡΡΡ ΠΊΠ°Π½Π΄ΠΈΠ΄ ΠΏΡΠΎΠΏΠΎΡΡΠΈΠΎΠ½Π°Π»ΡΠ½ΠΎ ΡΡΡΠ΅ΡΡΠ²Π΅Π½Π½ΠΎ ΡΠ½ΠΈΠΆΠ°Π΅ΡΡΡ, Π° Π»ΠΈΠ·ΠΎΡΠΈΠΌ Π² ΡΠ°ΠΊΠΈΡ
ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΡΠΏΠΎΡΠΎΠ±ΡΡΠ²ΡΠ΅Ρ ΡΠ°Π·ΡΡΡΠ΅Π½ΠΈΡ Π±ΠΈΠΎΠΏΠ»Π΅Π½ΠΊΠΈ
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