Effect of second phase particles on mechanical properties and grain growth in a CoCrFeMnNi high entropy alloy

Effect of annealing of a cold-worked CoCrFeMnNi alloy at temperatures of 500-900°C for 1-50 h on the structure and mechanical properties was studied in the present wor

Microstructure evolution of a ti/tib metal-matrix composite during high-temperature deformation

A Ti/TiB metal-matrix composite (MMC) was produced by spark plasma sintering using a Ti-10wt.%TiB2 powder mixture at 850°C under a load of 40 MPa for 15 min. The microstructure evolution and mechanical behavior of the Ti/TiB composite during uniaxial compression at the temperature range 500 - 1050°С was studie

Calculation of neutron radiation attenuation factor with Monte Carlo method

В докладе рассматривается моделирование возможных траекторий движения нейтронов с использованием метода Монте-Карло при прохождении сквозь однородную пластину. Представлен разработанный расчетный код на языке программирования С++, с помощью которого можно определить количество поглощенных, отраженных и прошедших через пластину нейтронов. Исходные данные включают характеристики материала, толщину пластины и количество рассчитываемых траекторий. Результаты работы будут использованы для верификации данных, получаемых с помощью высокопрецизионных расчетных кодов.In the report it is considered the simulation of possible neutron trajectories while passing through a homogenous plate with the help of Monte Carlo method. A developed calculated code using C++ programming language is presented. The code can be used to determine the amount of absorbed, reflected and passed through the plate neutrons. The initial data include the material characteristics, plate thickness and amount of calculated trajectories. The results of this work will be used for the verification of data received with calculation codes of high precision

Microstructure and texture evolution of a high manganese TWIP steel during cryo-rolling

The influence of rolling at 77 K and 293 K to a true strain of 2.66 on the microstructure and texture evolution and mechanical behavior of a TWIP Fe-0.3C-23Mn-1.5Al steel was quantified. The microstructure evolution at both temperatures of deformation was associated with an increase in the dislocation density and extensive twinning, following by the development of a cell structure and shear band

Effect of plastic deformation on the structure and properties of the Ti/TiB composite produced by spark plasma sintering

A Ti/17 vol % TiB composite material is produced by spark plasma sintering of a mixture of titanium and 10 wt % TiB2 powders at a temperature of 1000°C. Multiaxial isothermal forging is performed at t = 850°C to enhance the mechanical properties of the composit

Evolution of microstructure and mechanical properties of Tibased metal-matrix composites during high-pressure torsion

The microstructure and microhardness evolution of a Ti/TiB and Ti15(wt.%) Mo/TiB metal-matrix composites (MMC) during high-pressure torsion (HPT) at 400 °C was studie

Kinetics of recrystallization and grain growth in an ultra-fine grained CoCrFeNiMn-type high-entropy alloy

A novel high entropy alloy based on the CoCrFeMnNi system with substantial amounts of Al and C was studied. After cold rolling and annealing at 973-1273 K a duplex ultrafine grained structure composed of the recrystallized fcc grains and M23C6 and B2 particles was produced. Analysis of the coarsening behavior of grains and particles growth suggested that kinetics of both was controlled by volume diffusion. The apparent activation energy of structure coarsening during recrystallization was evaluate

Recrystallized microstructures and mechanical properties of a C-containing CoCrFeNiMn-type high-entropy alloy

The effect of cold rolling to 80% thickness reduction and annealing at 973-1373 K for 1h our on the microstructure and mechanical properties of a C-containing CoCrFeNiMn high-entropy alloy was studied. Cold rolling significantly strengthened the alloy to the yield strength of 1310 MPa. Annealing at 973 K or 1073 K resulted in incomplete recrystallization of an fcc matrix and M23C6-type carbide precipitations aligned with highly elongated grains/subgrains. Complete recrystallization occurred during annealing at 1173-1373

Scanning Electron Microscopy Study of Drilling Cuttings in Tomsk Oblast Sites

The research is focused on determining mineralogical composition of drilling cuttings by scanning electron microscope as well as imaging the sample surface of high resolution that allows studying the structural characteristics of the site. In addition, a number of other techniques permit obtaining information on chemical composition of sample in near-surface layers. The study in drilling cuttings by means of scanning microscopy has revealed the presence of titanium, iron, zirconium oxides, iron sulphide, barium sulphate. The former is a mineral that concentrates rare-earth elements, presumably monocyte, as well as uranium silicate, etc. The results obtained confirm the data of previous X-ray structural analysis, i.e. the study samples consist of alumosilicate matrix. Apart from silicon and aluminium oxides, the matrix includes such elements as Na, K, Mg. Such a composition corresponds to rock-forming minerals: quartz, albite, microcline, clinochlore, muscovite, anorthoclase

The ultradian rhythm of glucocorticoid secretion and the time course of target gene regulation

Glucocorticoid hormones (cortisol in humans and corticosterone in rodents) are secreted in discrete pulses during a day with a periodicityof approximately 1 h (ultradian rhythm), and this pattern is also maintained in plasma and extracellular fluid. However, the vast majority of studies on gene regulation by glucocorticoids typically assess gene responses regardless the ultradian rhythm. These experiments are usually performed using long-term stimulation with synthetic hormones (dexamethasone and triamcinolone), which form much more stable complexes with glucocorticoid receptor (GR) then natural hormones. This review summarizes the current scarce information, obtained in experiments mimicking the ultradian mode of natural hormone secretion in cultured cells and in animal models. The results of these experiments clearly demonstrate that ultradian stimulation by natural hormones induces rapid GR exchange with glucocorticoid response elements and leads to cyclic GR mediated transcriptional regulation (gene pulsing) at the level of nascent RNA. In contrast, synthetic glucocorticoids, having much higher receptor affinity, fail to disengage from nuclear receptors with sufficient speed to support the ultradian cycles, thereby uncoupling extracellular hormone fluctuations from appropriate receptor function at response elements. This alters RNA accumulation profiles dramatically. These findings suggest potentially important consequences of ultradian secretion. The transcriptional program induced by hormone pulses differs significantly from that generated by constant hormone treatment. Thus, treatment with synthetic glucocorticoids may not provide an accurate assessment of physiological hormone action