OBTAINING OF FERROSILICOCHROMIUM POWDER ALLOY BY SILICOTHERMIC REDUCTION AND STUDY OF THE MECHANISM OF THIS PROCESS

The process of obtaining a powder ferrosilicochromic alloy by the method of silicothermic reduction of local chromites and slags of copper smelters was investigated. The mechanism of this process has been studied. It is established that the best results are obtained in the case of slag / chromite ratio = 1: 1, when an alloy with microdispersed structure and high strength is obtained. The optimum composition of the resulting alloy is as follows: 35,1% Fe; 36,35% Si and 28,53% Cr, with a metal yield of 98,4%. The obtained alloy powder can be used as an acidified and alloying additive to chromium- and silicon-containing stainless composite materials. The aspects of the process for obtaining FeSiCr alloy have been developed. The maximum temperature (Tc) and the linear propagation velocity of the combustion wave (Uv) are determined graphically. The mechanism of the formation of FeSiCr in the SHS process is explained.The process of obtaining a powder ferrosilicochromic alloy by the method of silicothermic reduction of local chromites and slags of copper smelters was investigated. The mechanism of this process has been studied. It is established that the best results are obtained in the case of slag / chromite ratio = 1: 1, when an alloy with microdispersed structure and high strength is obtained. The optimum composition of the resulting alloy is as follows: 35,1% Fe; 36,35% Si and 28,53% Cr, with a metal yield of 98,4%. The obtained alloy powder can be used as an acidified and alloying additive to chromium- and silicon-containing stainless composite materials. The aspects of the process for obtaining FeSiCr alloy have been developed. The maximum temperature (Tc) and the linear propagation velocity of the combustion wave (Uv) are determined graphically. The mechanism of the formation of FeSiCr in the SHS process is explained

Exclusive photoproduction of J/ψJ/\psi in proton-proton and proton-antiproton scattering

Protons and antiprotons at collider energies are a source of high energy Weizs\"acker--Williams photons. This may open a possibility to study exclusive photoproduction of heavy vector mesons at energies much larger than possible at the HERA accelerator. Here we present a detailed investigation of the exclusive $J/\psi$ photoproduction in proton-proton (RHIC, LHC) and proton-antiproton (Tevatron) collisions. We calculate several differential distributions in $t_1, t_2, y, \phi$, as well as transverse momentum distributions of $J/\Psi$'s. We discuss correlations in the azimuthal angle between outgoing protons or proton and antiproton as well as in the ($t_1, t_2$) space. Differently from electroproduction experiments, here both colliding beam particles can be a source of photons, and we find large interference terms in azimuthal angle distributions in a broad range of rapidities of the produced meson. We also include the spin--flip parts in the electromagnetic vertices. We discuss the effect of absorptive corrections on various distributions. Interestingly, absorption corrections induce a charge asymmetry in rapidity distributions, and are larger for $p p$ reactions than for the $p \bar p$ case. The reaction considered here constitutes an important nonreduceable background in recently proposed searches for odderon exchange.Comment: 22 pages, 20 figures; dedicated to Kolya Nikolaev on the occasion of his 60th birthday; 4 figures and discussion adde

Production of Z^0 bosons with rapidity gaps: exclusive photoproduction in gamma p and p p collisions and inclusive double diffractive Z^0's

We extend the k_\perp-factorization formalism for exclusive photoproduction of vector mesons to the production of electroweak Z^0 bosons. Predictions for the gamma p \to Z^0 p and p p \to p p Z^0 reactions are given using an unintegrated gluon distribution tested against deep inelastic data. We present distributions in the Z^0 rapidity, transverse momentum of Z^0 as well as in relative azimuthal angle between outgoing protons. The contributions of different flavours are discussed. Absorption effects lower the cross section by a factor of 1.5-2, depending on the Z-boson rapidity. We also discuss the production of Z^0 bosons in central inclusive production. Here rapidity and (x_{\Pom,1}, x_{\Pom,2}) distributions of Z^0 are calculated. The corresponding cross section is about three orders of magnitude larger than that for the purely exclusive process.Comment: 19 pages, 14 figs, A. Cisek is married name of A. Rybarsk

Dielectric model of point charge defects in insulating paraelectric perovskites

Some point defects (i.e., oxygen vacancies) create deep trapping levels in the bandgap of the paraelectric phase ferroelectric crystals. Under applied DC field the traps release electrons via the Poole-Frenkel mechanism and become charged. The electric field of a point charge polarizes the crystal locally reducing its permittivity. In this paper a simple theory is proposed for calculating the DC field dependent apparent (measureable) permittivity of a paraelectric crystal with point charge defects. It is shown that the apparent permittivity of a paraelectric crystal may be sufficiently lower as compared with the defectless crystal. This reduction is in addition to the possible reduction of the apparent permittivity associated with the interfacial "dead" layers and strain

STUDY OF THE EXISTING SYSTEM OF LOGISTICS SUPPORT IN CONSTRUCTION

The article deals with the concept of logistics, presents particular logistical support in a number of countries. The role and significance of the subsystem of logistics in the construction industry. The problems of logistics in the field of construction. The article suggests measures to improve the system of logistics domestic construction industry

STUDY OF THE EXISTING SYSTEM OF LOGISTICS SUPPORT IN CONSTRUCTION

The article deals with the concept of logistics, presents particular logistical support in a number of countries. The role and significance of the subsystem of logistics in the construction industry. The problems of logistics in the field of construction. The article suggests measures to improve the system of logistics domestic construction industry

INVESTIGATION ON STABILITY OF TEXTILE MATERIALS FOR OVERALLS PROCESSED BY NEW BIOCIDAL PREPARATIONS

This article is devoted to the research of new promising biocidal preparations, in particular ethyl, allyl and methyl, which promote the improvement of the consumer properties of textile materials and increase their durability. The problem of protecting textile materials and products from microbiological destruction is complex and multifaceted, and its successful solution requires coordinated and focused efforts of specialists of various profiles. Of particular relevance is the search for effective ways to protect against microbiological destruction of textile materials. And today one of such methods of protection is to provide textiles with biocidal properties, which not only prevents the growth of bacteria, but can also provide a high level of wear resistance of tissues. The aim of the work was to study the impact of new low-toxic biocidal drugs on the stability of coloring of textile materials to the effect of various physical and chemical factors. In the research, the method and technology of providing biocidal properties to textile materials for the production of overalls, in particular, impregnation of textile materials in alcoholic solution of biocidal preparations, was developed. As samples were selected fabrics of different chemical composition, which are intended for the manufacture of overalls. The best results were obtained with dry friction, and, treatment, does not significantly affect the stability of color, and in the case of cotton-polyester fabric, on the contrary, even increases it. Low indicators of the stability of color to the action of wet friction is due to the low resistance of colors to water

Effects of α-amylase, endo-xylanase and exoprotease combination on dough properties and bread quality

Received: January 31st, 2021 ; Accepted: May 2nd, 2021 ; Published: May 6th, 2021 ; Correspondence: [email protected] enzymes composition is an actual alternative to chemicals to improve functional properties of flours and to generate changes in the structure of the dough and bread quality. The objective of this study was to analyze the individual and synergistic effects of enzymes preparation (α-amylase, endo-xylanase and exoprotease), newly produced in Russia, on dough properties and bread quality made from wheat flour with different amylolytic activity. Reofermentometric results revealed decreases in gas-forming capacity of dough by 10.0–13.9% when single α-amylase preparates were used. The α-amylase addition had significant effect on gas retention coefficient in flour possessed low amylolytic activity. The effect of endo-xylanase and exoprotease on hydration and amount of wheat gluten was established. The fractional composition of gluten proteins in the dough made with combination of endo-xylanase and exoprotease was established using Lowry method immediately after kneading and after fermentation. It was found that mainly water-soluble, alcohol-soluble and alkaline-soluble proteins were undergone by transformation. The bread with enzymes had a higher specific volume, porosity and aldehyde content and lower shape stability indicator than the control bread made without enzymes. Bread with enzymes was characterized by tenderer and not crumbly crumb with developed thin-walled uniform porosity compared to the control. The crusts were more brightly colored. The combined usage of α-amylase and endo-xylanase and exoprotease retarded bread staling during 5-day storage period. New enzyme composition may be a potentially strong candidate for future applications in the bread-making industry

Teaching Autonomous Systems at 1/10th-scale

Teaching autonomous systems is challenging because it is a rapidly advancing cross-disciplinary field that requires theory to be continually validated on physical platforms. For an autonomous vehicle (AV) to operate correctly, it needs to satisfy safety and performance properties that depend on the operational context and interaction with environmental agents, which can be difficult to anticipate and capture. This paper describes a senior undergraduate level course on the design, programming and racing of 1/10th-scale autonomous race cars. We explore AV safety and performance concepts at the limits of perception, planning, and control, in a highly interactive and competitive environment. The course includes an ethics-centered design philosophy, which seeks to engage the students in an analysis of ethical and socio-economic implications of autonomous systems. Our hypothesis is that 1/10th-scale autonomous vehicles sufficiently capture the scaled dynamics, sensing modalities, decision making and risks of real autonomous vehicles, but are a safe and accessible platform to teach the foundations of autonomous systems. We describe the design, deployment and feedback from two offerings of this class for college seniors and graduate students, open-source community development across 36 universities, international racing competitions, student skill enhancement and employability, and recommendations for tailoring it to various settings