Research of Influence Modification of Natural Concentrate on Quality Metal

Questions of increase of mechanical, technological and service properties of metal at minimum cost to produce it are relevant for the metallurgical enterprises. Modification of complex steel alloys containing reactive elements is one of the effective ways to improve the quality of steel. At the same time the direct costs for the use of modifiers are 0.2-0.3%, which little effect on the cost of production. The paper presents the results of the application of natural concentrates as a modifier steel. The effects on the metal quality changes due to the impact of the modification concentrates demonstrate the effectiveness of their application. As a result of modification decreased the content of nonmetallic inclusions and grain size. Reduction of impurity modified metal of was the cause more high plastic properties, especially, impact strength at ordinary and low temperatures of tests. Based on the experimental data evaluated hardening mechanisms that lead to a significant improvement of physic-mechanical properties of the metal workpiece after administration modifier

Analysis of Structure Destroyed Metal after Diffusion Heat Treatment

It was accomplished research of the structure steel which carbonitriding and subsequent heat treatment was exposed for its cause's destruction to discover. For measure quality field of metal were used methods optical, appearing electronic microscopy and X-ray diffraction. Therefore one of the principal problems were research phase composition, grain and dislocation structure of a metal the gear teeth. Mechanism of rising hear cracks in the gear teeth on different stages her making and their trajectories of evolution were determined

Calculation of The Lifetimes of Thin Stripper Targets Under Bombardment of Intense Pulsed Ions

The problems of stripper target behavior in the nonstationary intense particle beams are considered. The historical sketch of studying of radiation damage failure of carbon targets under ion bombardment is presented. The simple model of evaporation of a target by an intensive pulsing beam is supposed. Stripper foils lifetimes in the nonstationary intense particle can be described by two failure mechanisms: radiation damage accumulation and evaporation of target. At the maximal temperatures less than 2500K the radiation damage are dominated; at temperatures above 2500K the mechanism of evaporation of a foil prevails. The proposed approach has been applied to the discription of behaviour of stripper foils in the BNL linac and SNS conditions.Comment: 12 pages, 5 figure

Analysis of Structure Destroyed Metal after Diffusion Heat Treatment

It was accomplished research of the structure steel which carbonitriding and subsequent heat treatment was exposed for its cause's destruction to discover. For measure quality field of metal were used methods optical, appearing electronic microscopy and X-ray diffraction. Therefore one of the principal problems were research phase composition, grain and dislocation structure of a metal the gear teeth. Mechanism of rising hear cracks in the gear teeth on different stages her making and their trajectories of evolution were determined

Effect of tantalum on the tensile properties of 12%Cr martensitic steels for steam blades

Co-modified 12%Cr martensitic steels are perspective materials for steam blades for fossil power plants which are able to work at ultra-supercritical parameters of steam (T=620-650°C, P=2530 MPa

H-atom addition and abstraction reactions in mixed CO, H2CO and CH3OH ices: an extended view on complex organic molecule formation

Complex organic molecules (COMs) have been observed not only in the hot cores surrounding low- and high- mass protostars, but also in cold dark clouds. Therefore, it is interesting to understand how such species can be formed without the presence of embedded energy sources. We present new laboratory experiments on the low-temperature solid state formation of three complex molecules: methyl formate (HC(O)OCH3), glycolaldehyde (HC(O)CH2OH) and ethylene glycol (H2C(OH)CH2OH), through recombination of free radicals formed via H-atom addition and abstraction reactions at different stages in the CO-H2CO-CH3OH hydrogenation network at 15 K. The experiments extend previous CO hydrogenation studies and aim at resembling the physical&chemical conditions typical of the CO freeze-out stage in dark molecular clouds, when H2CO and CH3OH form by recombination of accreting CO molecules and H-atoms on ice grains. We confirm that H2CO, once formed through CO hydrogenation, not only yields CH3OH through ongoing H-atom addition reactions, but is also subject to H-atom-induced abstraction reactions, yielding CO again. In a similar way, H2CO is also formed in abstraction reactions involving CH3OH. The dominant methanol H-atom abstraction product is expected to be CH2OH, while H-atom additions to H2CO should at least partially proceed through CH3O intermediate radicals. The occurrence of H-atom abstraction reactions in ice mantles leads to more reactive intermediates (HCO, CH3O and CH2OH) than previously thought, when assuming sequential H-atom addition reactions only. This enhances the probability to form COMs through radical-radical recombination without the need of UV photolysis or cosmic rays as external triggers.Comment: 20 pages, 8 figure

АНАЛИЗ ДАННЫХ ФОРМАЛЬНЫМИ МЕТОДАМИ ОЦЕНКИ ПОКАЗАТЕЛЕЙ КРИТЕРИЕВ РЕЙТИНГОВАНИЯ В ПРОЦЕССЕ АККУМУЛИРОВАНИЯ СВЕДЕНИЙ О ДЕЯТЕЛЬНОСТИ ПРОФЕССОРСКОГО-ПРЕПОДАВАТЕЛЬСКОГО СОСТАВА

The article considers the development of formal methods of assessing the rating criterion exponents. The article deals with the mathematical model, which allows to connect together quantitative rating criterion characteristics, measured in various scales, with intuitive idea of them. The solution to the problem of rating criterion estimation is proposed.В статье рассматривается разработка формальных методов оценки показателей критериев рейтингования. Показана математическая модель, позволяющая связать между собой количественные характеристики критерия рейтингования, измеренные даже в различных шкалах, с интуитивным представлением о них. Приведено решение проблемы оценки критерия рейтингования

Beta-blockers and chronic kidney disease: a literature review

Chronic kidney disease (CKD) and cardiovascular diseases are widespread throughout the world and are closely related to each other. Sympathetic hyperactivity, characteristic of CKD, increases cardiovascular risk and accelerates the progression of kidney disease by activating beta-adrenergic receptors. Beta-blockers play an important role in preventing the negative effects of in creased activity of the sympathetic nervous system on the cardiovascular system and kidneys, can slow the progression of renal disease, and have proven effective in reducing overall and cardiovascular mortality and treatment of coronary heart disease, heart failure, arterial hypertension, and arrhythmias in patients with CKD. Despite this, beta-blockers are still underused in patients with CKD, especially in its later stages, including ESRD. Although there are currently no clear recommendations for the choice of any specific beta blocker in CKD, factors such as the CKD stage, presence of diabetes mellitus or reduced insulin sensitivity, and pharmacodynamics (cardioselectivity, α1-blocking- and vasodilating properties) and pharmacokinetic properties (metabolism, routes of elimination from the body, degree of binding to plasma proteins and dualizability) should be considered. At present, along with ACE inhibitors, AT1-receptor antagonists, and SGLT2 inhibitors, beta-blockers remain indispensable drugs for treating cardiovascular diseases with proven positive effects on the progression of kidney failure in patients with CKD. Their broader use in this population is expected to further reduce cardiovascular mortality and delay the initiation of renal replacement therapy

SURFRESIDE2: An ultrahigh vacuum system for the investigation of surface reaction routes of interstellar interest

A new ultrahigh vacuum experiment is described to study atom and radical addition reactions in interstellar ice analogues for astronomically relevant temperatures. The new setup – SURFace REaction SImulation DEvice (SURFRESIDE2) – allows a systematic investigation of solid state pathways resulting in the formation of molecules of astrophysical interest. The implementation of a double beam line makes it possible to expose deposited ice molecules to different atoms and/or radicals sequentially or at the same time. Special efforts are made to perform experiments under fully controlled laboratory conditions, including precise atom flux determinations, in order to characterize reaction channels quantitatively. In this way, we can compare and combine different surface reaction channels with the aim to unravel the solid state processes at play in space. Results are constrained in situ by means of a Fourier transform infrared spectrometer and a quadrupole mass spectrometer using reflection absorption infrared spectroscopy and temperature programmed desorption, respectively. The performance of the new setup is demonstrated on the example of carbon dioxide formation by comparing the efficiency through two different solid state channels (CO + OH → CO_2 + H and CO + O → CO_2) for which different addition products are needed. The potential of SURFRESIDE2 to study complex molecule formation, including nitrogen containing (prebiotic) compounds, is discussed

Degradation of the creep resistance of a Re-containing 10% Cr steel upon creep testing at low applied stress

New Re-containing steel is a promising material for steam blades of fossil power plants worked at ultra-supercritical parameters of the steam. This steel was subjected to creep testing at 650°C under the applied stresses ranging from 200 to 100 MPa. The steel exhibits excellent creep resistance at high applied stresses; the time to rupture comprises 10,987 hours after the creep test at 650°C/140 MP