bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of bovine tallow in butter using a comprehensive method
Authors: Nilchian Z. , Ehsani M. R. , Piravi-Vanak Z. , Bakhoda H.
Published: January 2020

The detection of animal fats such as tallow in butter using standard criteria is more difficult than vegetable fats. In order to perform a complete assessment, several methods are likely to be used together. In the experimental design of this research, compositional characteristics such as fatty acids, sterols and triacylglycerols, along with the conventional physicochemical characteristics of butter mixed with different percentages of tallow (0–15% w/w) were evaluated. An increase of less than 5% (w/w) in bovine tallow content in butter physicochemical tests, sterols and fatty acids could not indicate the adulteration level but the ratio of C6+8+10+12/C18 fatty acids, C52/C50، C52/C48, C52/C46 triacylglycerols, S1, S3, S5-value equation and C52 triacylglycerols could show this adulteration level in butter. Also, the successive use of fatty acids and triacylglycerols resulted in the capability to determine adulteration in butter including bovine tallow above 1% (w/w).
Enzyme-assisted three-phase partitioning: An efficient alternative for oil extraction from Sesame (Sesamum indicum L.)
Authors: Juvvi P. , Debnath S.
Published: January 2020

Three-phase partitioning (TPP) was explored for oil extraction from Sesamum indicum L. seeds. The process parameters, namely the salt concentration, slurry/t-butanol ratio and system pH were standardized. The optimum conditions for maximum oil recovery using TPP were an ammonium sulphate concentration of 40% (w/v), slurry/t-butanol ratio of 1:1 (v/v) and system pH of 5.0. The powdered seeds were subjected to enzyme-assisted three-phase partitioning (EATPP) which was pre-treated with pectinase, protease and a mixture of ɑ-amylase and amylo-glucosidase (1:1 ratio) followed by TPP (as standardized conditions) and its efficacy in recovering oil was compared with TPP and solvent extraction (SE). Out of all the enzymes studied, EATPP with pectinase resulted in the highest oil recovery (86.12%), which was higher than that of TPP (78.24%). The free fatty acids, saponification value and peroxide values were observed to be lower in the case of TPP and EATPP when compared to SE, indicating better oil quality.
Sulphur doses and application times on yield and oil quality of canola grown in calcareous soil
Authors: Younis M. , Muhammad A. , Alam S. , Jalal A.
Published: January 2020

Pakistan has been constantly deficient in its oil seed production and it is very difficult to meet the edible oil requirement of its ever-increasing population. A field experiment was conducted at the Agronomy Research Farm, The University of Agriculture Peshawar, Northern Pakistan during winter (2013–14). Five sulphur levels (15, 30, 45, 60 and 75 kg·ha-1) and times of application (at seedling, bolting and flowering stages) were used for the canola variety Abasin-95. The experiment was laid out in a randomized complete block design replicated four times on a 5 m × 3.2 m plot size. The results showed that the sulphur-applied plots gave the highest seed yield, biological yield, glucosinolate, erucic acid, oil content, protein content, oleic acid and linoleic acid compared to the control plots. Sulphur applied at the rate of 60 kg·ha-1 and applied at the bolting stage increased seed yield, biological yield, oil content, and protein content.
« The desert says nothing » : Elizabeth Temple et Edward Abbey, prophètes de la dégénérescence environnementale dans The Pioneers et Desert Solitaire
Authors: Maille Loïk
Published: January 2020

Près de cent cinquante ans séparent la publication de The Pioneers, roman inaugural du cycle des Leatherstocking Tales de James Fenimore Cooper, et Desert Solitaire, d’Edward Abbey. Cette distance temporelle offre une vision panoramique des métamorphoses de la wilderness, tant en terme de dégénérescence écologique que de représentation littéraire. Avec l’éveil d’une conscience environnementale, ce territoire se transfigure progressivement. S’il semble en premier lieu une source symbolique et esthétique de représentation du paysage au XIXe siècle, le statut de la wilderness évolue parallèlement à la découverte de son statut d’écosystème aux ressources périssables et finies, face aux ambitions infinies de la civilisation industrielle.
Les représentations de la femme dans l’univers oriental des Contes de Voltaire
Authors: Aliou Moufida
Published: January 2020

Les figures féminines des Contes de Voltaire sont, pour la plupart puisées dans le grand thésaurus oriental constitué essentiellement par le Coran, les récits de voyage, les « contes arabes » traduits par Antoine Galland et intitulés Les Mille et Une Nuits, la Bibliothèque Orientale de Barthélémy d’Herbelot ou dans les relations recueillies de la bouche de personnes qui ont visité divers pays d’Orient. Voltaire multiplie les figures issues de ce contexte culturel encore inconnu du lectorat européen contemporain : femmes claustrées dans des harems ou sérails, femmes voilées, femmes captives de corsaires, odalisques, reines… La peinture de tous ces personnages féminins nous a placée devant des questions pressantes sur les sources de l’accès de Voltaire à cet univers quasi mythique qui constitue le fondement de sa représentation d’un Orient né sous sa plume d’une sorte de syncrétisme que forment des ouvrages miroirs d’altérités. Voltaire emprunte à l’Orient tout un éventail de figures de femmes dont les portraits, emblématiques de cet univers, semblent être convoqués dans un souci d’ordre esthétique, certes, mais qui sert notamment d’assise à un militantisme en faveur du bonheur humain, notion phare amenant vers sa lumière scintillante tous les écrits se réclamant de cette vénération vouée à la raison.
Improvement of Mechanical and Electrochemical Properties of Titanium Thin Films Deposited by Duplex Treatment
Authors: Alim Mohamed Mounes , Hadj-Larbi Fayçal , Tadjine Rabah
Published: January 2020

The mechanical and electrochemical properties of a low carbon steel alloy were improved with titanium (Ti) nitrides thin films. A nitriding process ensures the adhesion of the deposited thin films and provides the nitrogen source involved in the formation of the desired nitrides. A hybrid reactor was used to permit this duplex surface treatment and to avoid the oxidation of our samples. The X-ray diffraction revealed the formation of nitrided phases (TiN and Ti2N). The scanning electron microscopy showed an improvement in the adhesion of the deposited thin films with increasing negative bias voltages. The nanohardness of the duplex treated samples was found to be improved. The results obtained after the corrosion tests indicate a reduction of electrochemical activity and therefore an improvement of corrosion resistance.
A PV-Active Power Filter Interface Scheme for Three Phase Balanced System
Authors: Slimani Abdeldjalil , Tanjaoui Mohammed Nacer , Boutadara Abdelkader , Saihi Lakhdar , Bailek Nadjem , Adel M. Sharaf , Koussa Khaled
Published: January 2020

This paper presents a modified hybrid Controller based on instantaneous power-fuzzy controller (IPFLC) for a shunt active power filter (SAPF). The current produced by the AC source is polluted by harmonics injected by the non-linear loads. The supply system requires filtering by suppressing harmonic currents to improve power quality at interface bus. The filtering system consists of an LC filter and a SAPF. The proposed IPFL Controller for the SAPF is based on a combination of the p-q instantaneous power and the fuzzy logic strategy. In this part, two cases are studied, first the active filter is connected only to a capacitor by its dc side, and second case where the active filter is connected to a photovoltaic source or to a battery. The effectiveness, robustness and the dynamic speed of the proposed controller is validated and assessed using dynamic digital simulation. Digital Simulation results validated also the effectiveness of the active filter scheme with modified controller in reducing the source current THD from 25.87% to 0.83% which largely meets the standards of IEEE STD and International Electro-technical Commission (IEC). Digital Simulation and validation used MATLAB-SIMULINK Software Environment.
Investigation of Stagnant Zones in Centrifuges
Authors: Filimonov Maksim I. , Novikov Andrey E. , Lamskova Mariya I.
Published: January 2020

Centrifuging is one of the most complicated technological processes, and centrifuges are the ones of the most complex technological machines. Not all the questions of the theory of centrifuges have been sufficiently developed, in particular, there is no reliable description of hydrodynamic flows in the process of centrifugation, resulting in the impossibility of an accurate prediction of the separation of heterogeneous systems. Circulation and stagnant (“dead”) zones often appear in centrifuge casings, which lead to uneven residence time of the fluid flow and reduced productivity of the centrate. To improve the construction of these machines, as well as to substantiate the technological mode of their operation, experimental studies were conducted, aimed at identifying the dependence between a proportion of the stagnant zones and the rotor speed. Determination of proportion ofthe stagnation zones was carried out by processing and analyzing the response curves obtained at the centrifuge output, after creating a pulsed input disturbance. Studies have shown that an increase in the rotor speed from 350 to 750 rpm leads to a decrease in proportion of the stagnation the stagnation zones in the centrifuge from 12% to 4.5%, thereby contributing to the intensification of the centrifugation process.
Electrolytic Behavior of Nickel in Polarization by Variable Asymmetric Rectangular Current in Alkaline Solutions
Authors: Demiyan V.V. , Zelenskaya E.A. , Shabelskaya N.P.
Published: January 2020

The paper presents experimental data on nickel oxidation during electrolysis under rectangular alternating current in alkaline solutions, when the cathode pulse (Iк ) is greater than the anode pulse ( Iа ). During the process, intense nickel destruction occurs forming bivalent oxide powder. Under prolonged electrolysis, this powder deposits at the bottom of the electrolyzer in the form of a sponge. The results obtained can be used to produce active mass in the porous nickel oxide electrode of a chemical current source.
Creating and Studying of Enterosorbent with Harsh-Fixed Antioxidants which Have Enzymatic Properties
Authors: Kapizova Alfiya M. , Alikova Tamara V. , Omarieva Luisa V.
Published: January 2020

The enterosorbent-antioxidant is created on the basis the silica clay of the Astrakhan region as a result of theoretical and experimental studies. The antioxidant properties enterosorbent SV-1-AO were studied. The studies to elucidate the possible deactivation of hydrogen peroxide in the gastrointestinal tract of animals in the application of enterosorbent SV-1-AO were carried out. The practical application of the product of the sorption concentration of antioxidant enzymes to ensure the safety of life is shown
Novel Catalytic Systems Based on Platinum Catalysts
Authors: Kurunina G. M. , Ivankina O.M. , Butov G. M.
Published: January 2020

The paper presents a method for the production of 1% platinum catalysts containing oxides of rare-earth elements (REE); it also dwells upon the results of analyzing such catalysts by scanning electron microscopy (SEM), x-ray diffraction analysis (XDA), and thermal analysis (DTA-TGA).
Studies on Microwave-Plasma Treatment of Froth Flotation Tailings
Authors: Kozhonov Almaz , Samsaliev Anvar , Toporkova Yulia I.
Published: January 2020

An efficient technology is currently being searched for the processing of aged enrichment gold-containing tailings at the «Solton-Sary» enrichment plant, Kyrgyzstan. In this paper, the effect of microwave-plasma exposure on aged tailings and further gold extraction using froth flotation were investigated. Microwave-plasma treatment of the material was carried out in the presence of the following materials: charcoal, coal/quartz and molybdenum sulfide. Microwave-plasma treatment allowed to improve the quality of flotation concentrates in terms of the gold content from 130 ppm to 227 ppm. The design of plasmatron and methodology of plasma treatment were proposed. The results shown in this paper are valuable for mining organization in terms of searching for new industrial waste processing approaches and for broadening their raw materials base.
Reaction of Spot Radioactive Source with the Energy of 661.7 KeV on the Modification in the Structure of Surface Layer of Metal Composite Material
Authors: Matyukhin Pavel V.
Published: January 2020

This paper presents the results of studies of the composite metal radio-protective building material by method of atomic-force probe microscopy, before and after its irradiation with gamma rays of 661.7 keV and absorbed dose up to 2 MGy. Composite metal material is based on the filling of hematite iron ore concentrate and aluminum matrix. This composite material has high technical (physical and mechanical) and radio-protective proprieties. The composite is planned to be employed as a bearing structure at various nuclear facilities.
The Effect of Different Oxidants on Extraction of Uranium from Low Grade Ore
Authors: Kanayev Ashimkhan T. , Valiyev Khussain , Bulaev Aleksandr
Published: January 2020

The effect of different oxidants on extraction of uranium from low grade ore was studied. Leaching was performed using sulfuric acid solutions at a concentration of 10 to 30%. Ferric sulfate Fe2(SO4)3, ammonium persulphate (NH4)2S2O8, and potassium permanganate KMnO4 at different concentrations were used as oxidants in different variants of the experiment. In addition, solutions collected at Vostok deposit containing 6.86 g/L Fe3+ and 106 cells/mL of the bacteria Acidithiobacillusferrooxidans were used for leaching. The rate of uranium extraction with sulfuric acid solutions without oxidants was low and did not exceed 19.4%. Addition of oxidants made it possible to increase rate of uranium extraction. In the presence of ferric sulfate, ammonium persulphate, and potassium permanganate rates of uranium extraction were up to 68, 95.2, and 69.6%, respectively. The rate of uranium leaching in the experiments with the AMD sample was high and reached about 95%. Therefore, it can be concluded that using not only oxidizing agents, but AMD, which are formed during the natural oxidation of sulfide minerals contained in the ore of the deposit, can significantly increase the rate of uranium recovery.
Modeling Stress Deformed State Upon Contact with the Bodies of Two-Phase Microstructure
Authors: Belyak Olga A. , Suvorova Tatiana V.
Published: January 2020

In this paper, the problems of directional modeling of the tribological properties of composites by introducing oils into them are considered. The contact problem of moving a flat punch, taking friction into account, on a heterogeneous semi-infinite media is considered. The Biot-Frenkel equations are taken into account. Mechanical constants included in the defining relations are found on the basis of the effective medium method and confirmed by numerical finite element method simulation. The solution of the contact problem is reduced to an integral equation of the first kind with a logarithmic kernel, the numerical solution of which is based on an iterative algorithm. The dependences of the contact stresses for the oil-filled composite on the porosity, the volume of applied filler, and the speed of the movement of the punch are investigated.
Improving the Bio-Resistance of Cement Concretes by Means of Fungicidal Poly-Functional Modifiers
Authors: Kosukhin Mikhail M. , Kosukhin Andrei M. , Starostina Irina V.
Published: January 2020

The research findings of physical and chemical properties of heavy and light concretes, contaminated with water suspension of mold fungi spores, are presented. It is noted that the concretes’ funginertness (resistance to fungi) is significantly influenced by their age, porosity and the alkalinity of medium. In the course of time the strength of concrete decreases, which is conditioned by the activation of mold fungi growth processes, as a result of de-alkalization of concrete, due to carbonization of cement stone and release of organic acids into the material. To improve the concrete’s resistance in biologically aggressive media, it is suggested to modify concrete with a new poly-functional fungicidal modifier, obtained on the basis of resorcine production waste. It has been demonstrated that the addition of resorcinol-formaldehyde oligomers to concrete mix completely inhibits mold fungi growth and allows obtaining concretes with the increased density and strength, which can be used in conditions of biologically aggressive media. The strength characteristics of the cement stone with the researched modifiers are not reduced at mold fungi spores’ contamination, but, on the contrary, slightly increase, due to the increase of cement paste fluidity, decrease of W/C ratio, reduction of micro-cracks in concrete and compaction of its structure, due to the peptizing action of the modifier.
Study of the Influence of Refractories Structure on the Thermomechanical Properties of Tunnel Kiln Equipment Lining
Authors: Lonzinger Tatiana M. , Skotnikov Vadim A. , Sukharev Alexey M.
Published: January 2020

A study of the influence of refractories’ structure on the thermomechanical properties of the lining of the equipment of tunnel kilns has been carried out. The lining of kiln trolleys is subjected to a mechanical stress distributed evenly over the entire area and the most dangerous to brittle materials, as well as to tensile thermal stresses. The magnitude of the tensile thermal stress depends on the material and the structure of the lining. The mechanisms of destruction of products made of fireclay and liquid concrete have been studied. Mineralogical and petrographic analysis of fireclay refractories have been used, as trolley lining has established metasomatic interaction of the lining with the vapor-gas component of the kiln, as well as with the metal of the trolleys. Monolithic products, made of low-cement concrete with corundum filler, are characterized by high strength and resistance to abrasion. The total value of compression and thermal expansion stresses for them is 3.08 MPa, which is half the value of those of fireclay. When conducting the research to optimize the composition of trolley lining, a technology for manufacturing two-layer concrete blocks, combining the advantages of compositions, based on corundum and fireclay, has been developed. The chemical and granulometric composition of fireclay-based concrete in the lower thermal insulation layer and electrocorundum-based concrete in the upper reinforcing layer were selected in such a way, as to ensure similar values of linear thermal expansion coefficients and prevent possible destruction along the boundary between the layers during the operation.
Study of the Suspension Stability of Titanium Dioxide of Anatase Modification for Self-Purifying Fine Concrete
Authors: Lukutsova N.P. , Efremochkin R.A. , Golovin S.N.
Published: January 2020

The suspension stability of the titanium dioxide of anatase modification, obtained by ultrasonic dispersion (USD) at the ultrasound frequency of 35 kHz in the aqueous medium of the stabilizer for self-purifying fine concrete as a finishing material for building envelope, is studied. The extreme dependence of the zeta potential on the ultrasonic dispersion parameters of titanium dioxide in the aqueous medium of the surfactant on the basis of sodium salts of naphthalene sulfonic acid and formaldehyde condensation products is established. Various variants of the sequence of the surfactant introduction into the titanium dioxide suspension are analysed. The ratio between TiO2 and the stabilizer, at which the zeta potential exceeds the threshold value of 30 mV and the suspension stability is maintained during 15 days, is determined. The optimal sequence of the suspension components introduction and the ultrasonic dispersion time are established. The influence mechanism of intermittent surfactant introduction on stabilization of the suspension of titanium dioxide of anatase modification is offered. The dependences of the fine concrete strength on zeta potential of the studied suspensions are obtained.
Physical-Chemical Studies and Evaluation of the Suitability of Chernoyarskoe Deposit’s Diatomite for the Synthesis of Foam Glass
Authors: Yatsenko Elena A. , Smoliy V.A. , Chumakov A.A.
Published: January 2020

The macro- and microstructure is investigated by microscopic analysis methods. The elemental, granulo-metric and mineralogical composition of diatomite of the Chernoyarskoe deposit is determined. As a result of complex thermal analysis, using a differential scanning calorimeter, intervals of continuous dehydration of diatomite were studied, as well as polymorphic transformations of quartz and other minerals. Physical-chemical methods of research have discovered that diatomite of the Chernoyarskoe deposit contains amorphous silica, quartzite, clay impurities, opal and minor amounts of calcite, mica, zeolite, and so this diatomite is a promising raw material for the synthesis of foam glass.
Assessment of Fire Safety of Coatings Based on Silicate Paint Sol
Authors: Loganina Valentina , Mazhitov Yerkebulan B. , Skachkov Yuri Petrovich
Published: January 2020

The results of the study the fire safety of coatings, based on silicate and sol silicate paints, are presented. The rapid method of the fire tube (based on the definitions of the duration of self-combustion or smoldering and on the mass loss of the sample after exposure to an open flame) established that the coatings belong to the group of non-flammable material, for coatings, based on poly-silicate solutions, have a lower loss of mass, in comparison with coatings based on liquid glass. At the flammability test on the TPR it was established, that coating based on potassium liquid glass and potassium poly-silicate solution did not ignite seen, even at a temperature of 760 degrees. There is no smoke emission. However, a change in the shape and color was recorded. The weight loss of the sample of the coating, based on potassium liquid glass, was 30.14% by weight, and the coating sample, based on the potassium poly-silicate solution, was 27.14%. The evidence of improvement of fire hazard characteristics of coatings based on poly-silicate solutions is obtained.
Prospects for the Development of Building Ceramics, Based on Stale Slags from the Non-Ferrous Metallurgy of Orenburg
Authors: Gurieva Victoria A. , Ilyina Anastasia A.
Published: January 2020

The article deals with the problems of using wastes formed after extraction of copper, nickel, gold, etc. from slags. A review of existing developments in the field of using technogenic products for the production of ceramic building materials with desired properties was carried out. The results of the study of the prospects of using stale slags from non-ferrous metallurgy on the example of the slags from the Mednogorsk Copper-Sulfur Plant of the Orenburg region in combination with fusible clay from the Alimsaysky deposit for the production of ceramic brick are presented. The data of studying the technological properties of raw materials, the development of compositions are given. The effect of the material composition of the clay / slag mixture on the strength, shrinkage, water absorption and density of experimental samples – bricks after calcination in the range of 900– 1200 ° C is determined.
The Economic Efficiency of the Development of Dry Mixes with the Supplement Based on Calcium Hydrosilicates
Authors: Pyshkina Irina Sergeevna , Zhegera K.V.
Published: January 2020

Provides information about the effectiveness of the introduction of modifying supplement in the formulation of dry mixes. Presents information about the technology of synthesis of supplement based on calcium hydrosilicates. It is established that the supplement has a high activity. A recipe for a lime dry mixes is presented using a supplement based on calcium hydrosilicate, synthesized in the presence of diatomite. The economic efficiency of the developed dry mixes with the use of calcium hydrosilicates has been calculated.
The Mechanical Properties of the Pipe Steel after Rolling at the Plate Mill
Authors: Platov Sergey I. , Nekit V.A. , Krasnov M.L.
Published: January 2020

A study of the mechanical properties of the finished metal products was carried out. All types of metal products are subjected to continuous quality control, both on the production output at the manufacturer of billets, and on the production entrance at the consumer of metal. Control subject are: strength characteristics (tensile strength σв and yield stress σ02 and the characteristics of plasticity (relative elongation δ and relative necking ψ). The pipe steels have another important controlled characteristic: the impact toughness КСU-60. All the test methods are the destroying ones and are characterized by high complexity. The task of reducing the types of tests, the introduction of a comprehensive indicator of product quality is an urgent technical task. The purpose of this work is to study the regularities of changes in the indicators that determine the quality of the sheet metal from the pipe steel.
Simulation of High-Speed Cutting Using Deform 3D Software
Authors: Gurevich Leonid Moiseevich , Novikov Roman , Bannikov Alexander
Published: January 2020

The paper presents the result of the simulation of high-speed hot cutting process for ordinary and new saw geometry, using the Deform 3D software package. It was shown that the use of an additional side rake angle allows to controllably leave burr on one side of the work-piece only, and shift max stress from the saw gullets to the top of teeth.
On the Role of Gamma-Alpha Transformation in the Increase of the Fracture Toughness of Maraging Steel
Authors: Sukhikh Arkadiy A.
Published: January 2020

Based on the results of the static crack resistance tests, the contribution of the strain-induced γ→α-transformation into the fructure toughness of steel N18K9M5T with two-phase (α+γ)-structure has been assessed.
Calculation of Phase Composition of α- and Near-α- Titanium Alloys
Authors: Vodolazskiy Fedor V. , Gornostaeva E.A. , Illarionova S.M.
Published: January 2020

The thermodynamic calculation of the phase composition of the PT-1M, PT-7M, Ti-3Al-2.5V alloys versus temperature is performed using the Thermo-Calc software. The comparison of calculation results with the available experimental data is made.
Determination of Rational Technological Parameters of Co-Extrusion Processing of Secondary Polymeric Materials by the Method of Physical Modeling
Authors: Dyadichev Valery V. , Kolesnikov Andrey , Dyadichev A.V.
Published: January 2020

The scientific article presents a physical model of the technical process of co-extrusion processing of secondary polymeric materials. A set of tools for automated control and monitoring of the model is considered, which allows to adjust smoothly the values of the rotational speeds of screws of extruders, the temperatures in the material heating zones and the pressure at the outlet of the co-extrusion head. The results of experiments to determine the temperature of the parison over a cooling time and the effect of screw speed and pressure in the head on the quality of mixing components are given. The results obtained by physical modeling confirm the correctness of the authors' calculations performed using the proposed mathematical models. Thus, it is possible to continue research in this direction, the result of which will be new designs of co-extrusion equipment, allowing to process efficiently polymeric waste into new high-quality products.
About Impact Strength and Thermal Properties of Steel Melts
Authors: Makhneva Tat’ana M. , Dementyev Vyacheslav B. , Makarov Sergey S.
Published: January 2020

The comparable study of the structure and structure-sensitive properties of the melt of steel 08H15N5D2T and two melts prepared by electro-slag re-melting (ESR) and vacuum-arc re-melting (VAR) of the steel has been carried out. The temperature dependences have been obtained for the kinematic viscosity, density, surface tension, electrical resistance, and magnetic susceptibility. The short-range structural order of the ESR and VAR melts has been studied by direct diffraction methods. The connection between the method of re-melting and the level of impact strength (KCU) has been established. The reasons for the appearance of the difference in the structure and properties of ESR and VAR steel are discussed.
Thermodynamic Regularities of Nuclei Growth during Crystallization of Metastable Alloys
Authors: Dudorov Maxim V. , Drozin Alexander D. , Chernobrovin Victor P.
Published: January 2020

The process of crystal growth in a metastable multicomponent melt has a high speed of the solidification front, which captures atoms of some other components. As a result of such a growth, at the surface of the growing crystal the effect of “impurity capture” is observed, and the concentrations of components significantly deviate from the local equilibrium. Under such conditions, the conventional physico-chemical methods for description of processes at the interfacial surface become inapplicable. Therefore, a new variational approach was applied for an integrated description of diffusion and thermal processes at the phase interface. The growth rate of crystal nucleus in a metastable melt was obtained, using the methods of non-equilibrium thermodynamics. The developed approach allows estimation of the degree of metastable effects influence on a crystal growth rate.
The Method of Testing Cylindrical Specimen for Torsion in Order to Determine the Rheological Properties of Materials Sensitive to the Strain Rate
Authors: Erpalov Mikhail , Pavlov Dmitry
Published: January 2020

The article provides an overview of existing methods of testing specimen for torsion, in order to determine the rheological properties of materials. In addition, the approaches to the post-processing experimental data, obtained in the form of torque-twist angle curve, are reviewed. It is shown that there is no universal and reliable method to study the rheological properties of materials that are sensitive to the strain rate. This paper proposes the new testing method that takes into account the effects of strain rate hardening initially. This method is that the torsion tests are carried out with the variable grips acceleration. The post-processing of obtained experimental data can be carried out with the use of modified Nadai method. In addition, with the use of mathematical modeling it is shown that the new method is reliable, regardless of material properties. The application for invention of the new testing method No2018132149 was directed in Federal Institute of Industrial Property on September, 7, 2018.
Microanalysis of Additive Products from Electro-Erosion Cobalt-Chrome Powders
Authors: Ageev Evgeniy V. , Altukhov A.Y. , Valguzov D.I.
Published: January 2020

The results of microanalysis of additive products from electro-erosive cobalt-chrome powders are presented. It has been established experimentally that the obtained samples of additive products from powders, obtained by electro-erosive dispersion of cobalt-chrome wastes in alcohol, have a microcrystalline structure with a porosity of less than 0,78%. The obtained experimental data can be used in the development of promising resource-saving technologies for the manufacture of machine parts.
Young Modulus at High Temperatures
Authors: Shinkin Vladimir N.
Published: January 2020

The dependence of the young modulus of metals and alloys on the high temperature must be taken into account in metallurgy in the hot rolling of steel sheet on sheet-rolling mills, hot flattening of steel sheet in the sheet straightening machines, press forming forgings from hot steel sheet, hot volume stamping of metal products, and so on. For example, on the mill 5000 by SMS Siemag, the sheet-rolling of steel strips from the hot slabs at the stand Quarto (the maximum force of 120 MN) occurs at a temperature from 750 °С to 1050 °С, but the pre-flattening of hot steel strip on the five-roller sheet-straightening machine by SMS Siemag occurs usually in the temperature range from 600 °С to 760 °С. In this paper, based on the analysis of experimental data about the dependence of the young modulus for various steel alloys, the analytical dependence of the young modulus on temperature is obtained.
Improvement of Methods of Calculation of Forces in Hot Strip Rolling
Authors: Baranov Georgy L.
Published: January 2020

A new solution Karman’s equation with the Mises plasticity condition is proposed for determining contact stresses in the slip zones for hot strip rolling. Replacement of the precise plasticity condition by an approximate condition in terms of primary stress leads to a substantial decrease in the length of slip zones and to increase of the rolling force. It was shown that, even at high frictional coefficients, the length of slip zones forms a significant part of the length of deformation region. On the basis of the obtained solutions the techniques for plotting curves of the normal contact stresses, determining the length of the slip zones, the neutral position of the cross section and rolling force refined.
Process Development for Solid Fuel Use at Siderite Ore Roasting in Shaft Furnace
Authors: Yur'ev Boris P. , Dudko Vyacheslav A.
Published: January 2020

Lean coal burning kinetics was studied and the main burning rate dependence on oxygen content in gas phase and heating rate was obtained. Preliminary dressed lump siderite ore from Bakal deposit with the fraction of 18-25 mm and average iron content of 35% was roasted in a pilot unit in neutral (low reducing) atmosphere, obtained by coal grate firing. It was established that such roasting allowed iron oxidation level reduction, as compared to roasting in oxidizing atmosphere and iron content increase in the roasted product. The evaluation results allowed development of a roasting process for siderite ore in neutral (low reducing) atmosphere and designing of a shaft furnace operating on solid fuel. Such roasting process is of a certain interest, as far as saving the insufficient fuel types, and predominantly natural gas, is concerned.
A Simulation of the Post-Bending Process of the Pipe Billets for Welded Pipe Manufacturing
Authors: Frunkin Dmitry , Gurevich Leonid Moiseevich , Novikov Roman
Published: January 2020

The paper presents a result of the simulation of the post-bending process of the pipe billet, using the MSC.Marc software package. It was shown that the use of a standard method for carrying out post-bending process leads to the formation of various defects, such as a variable gap between the edges along the pipe axis, vertical waves and bends at the edges, as well as a decrease in a sheet thickness on the edges.
Effect of Process Parameters on Quality of Ti-6Al-4V Multi-Layer Single Pass Wall during Direct Laser Deposition with Beam Oscillation
Authors: Shalnova S.A. , Klimova-Korsmik O.G. , Turichin G.A. , Gushchina M.O.
Published: January 2020

In this paper, the effect of process parameters on quality of fabricated wall, the phase composition, microhardness, and mechanical properties of the Ti-6Al-4V titanium sample, obtained by direct laser deposition, was considered. To determine the characteristics of the samples the X-ray diffraction, scanning electron microscopy, Vickers microhardness measurements, and uniaxial tensile tests were used. It is shown that the process parameters with the same speed, oscillation amplitude and peak value of heat flux have a similar wall thickness but different waviness with high mechanical properties.
Formation of Coatings under the Action of Laser Radiation in Liquid Media
Authors: Ivashchenko A.I. , Kochuev Dmitry , Davydov Nikolay
Published: January 2020

The influence of the chemical composition of the substrate material on the chemical and phase composition of the formed coating was investigated. A number of experiments aimed at studying the interaction of titanium alloys with ultrashort laser pulses in different reaction media was carried out. A new method for the formation of titanium carbide under the action of ultrashort laser pulses on the surface of a titanium sample in a liquid hydrocarbon and liquid nitrogen medium is described. The description of the experiment is presented. The treated surface was investigated using a scanning electron microscope. Raman spectra from the surface of treated titanium alloys under different exposure conditions are obtained.
Analysis of Electron Density Distribution in the CuAlO2 System
Authors: Pogoreltsev A.I. , Matuhin V.L. , Plotnikova J.D.
Published: January 2020

The results of earlier studies, using the NQR method 63.65Cu of the compound of the transparent conductive oxide CuAlO2, were used to study the topology of the distribution of the electron density in this compound. It was shown that for Al – O and Cu – Cu pairs, the formation of a bond most likely proceeds according to the type of closed shells, and in the “copper” plane there can be a noticeable number of free electrons. As for the copper – oxygen bond, we can assume the formation of O-Cu-O chains with a covalent bond. The noticeable difference in the character of the electron density distribution in mutually perpendicular planes suggests a certain anisotropy of conductivity in a given compound.
Features of the Formation of Various Functional Coatings of SHS Mechanical Composites Using Gas Detonation Spraying Technology
Authors: Sobachkin Alexey , Sitnikov A.A.
Published: January 2020

The present work is devoted to the determination of the characteristics of the deposition of coatings for various areas of technology, using the technology of gas detonation spraying of powder SHS mechanical composites. In the work, the most rational modes of coating deposition were determined, macro-and microstructures, surface topography, as well as coating properties (antifriction, micro-hardness, wear resistance) were investigated, and energy dispersion and X-ray phase analysis of raw materials and gas detonation coatings were carried out.
Study of Cavitation Erosion-Corrosion Resistance of Thermally Sprayed Ni-Based Coatings Prepared by HVAF Process
Authors: Alwan Hussam L. , Korobov Yury S. , Soboleva N.N. , Lezhnin N.V. , Makarov A.V. , Deviatiarov M.S.
Published: January 2020

In this study, two Ni-based coating materials, namely NiCrMoNb and NiCrBSi, have been applied using High Velocity Air Fuel (HVAF) thermal spraying process. The performance of the coated surface in resistance to cavitation erosion-corrosion of both coating materials, has been evaluated using an ultrasonic vibratory method. The cumulative material loss and erosion rate curves of the two coatings have been discussed. Surface topography, microhardness, macroscopic images, and scanning electron microscope (SEM) micrographs were used to characterize the coatings before and after the cavitation test. The cavitation results showed that the NiCrMoNb coating surface has exhibited better performance than the NiCrBSi coating surface under the same test conditions. The total cumulative weight loss of the NiCrMoNb coating was about 1/3 that of the NiCrBSi coating. SEM micrographs of the eroded surfaces showed that the surface layer of the NiCrBSi coating was more damaged, compared to layer of the NiCrMoNb coating. Overall, the NiCrMoNb coating can be effectively used against the cavitation wear, due to its superior performance.
Quantitative Assessment of Dissipative Properties of Superficial Structure of the Steel 25XM Strengthened by Pulse Laser Influence
Authors: Kim Vladimir A. , Thein Aung Ngwe
Published: January 2020

The superficial structure strengthened by laser radiation is formed in no equilibrium conditions of interaction of material with the high-concentrated energy stream. Education and development of such structure is realized on synergetic algorithm of process of phase and structural transformations. Dissipative properties of the strengthened structures can be described a complex of quantitative indices, such as amount of "dark" microstructural objects on the single surface area of a micro section and the average density of borders, calculated according to images of microstructures by means of special programs .Nature of distribution of microstructural indicators on depth of the strengthened layer depending on the modes of laser influence and their correlation with a micro hardness is shown in article.
Investigating of Nitric Acid Leaching of High-Sulfur Copper Concentrate
Authors: Rogozhnikov Denis A. , Shoppert Andrey A. , Karimova L.M.
Published: January 2020

This article describes the problems of deterioration of the quality of processed raw materials due to depletion of mineral resources. It is proposed to use nitric acid for the processing of complex refractory low-grade concentrates containing non-ferrous and noble metals. It was found that the studied concentrate contains: sphalerite (26.9 %), pyrite (22.0 %), chalcopyrite (19.9 %), silica (13.9 %), alumina (5.5 %), galena (1.7 %), oxidized forms of iron (Fe2O3) (12 %). Gold and silver are associated with sulfide minerals. Typical reactions of interaction of these minerals with nitric acid are considered. A sufficiently high thermodynamic probability of these reactions in a wide temperature range is established. With the use of mathematical methods, the optimal conditions of the process of nitric acid leaching are selected: the ratio of L:S = 5:1; the concentration of nitric acid 10 mol/L; the duration of the process is 60 minutes. In this case, the extraction of copper, zinc, iron and sulfur into the solution was 99.00 %, 99.84 % 98.60 %, 88.51 %, respectively.
Strength Properties of Composite Board Materials Based on Ligno-Cellulose Fiber, Modified by Steam Explosion Treatment
Authors: Prosvirnikov Dmitry B. , Timerbaev Nail F. , Sattarova Zulfiya G.
Published: January 2020

The article presents the results of using activated lingo-cellulosic material, obtained by the method of steam explosion treatment, as the basis for the production of composite pressed boards without a binder. The influence of steam explosion treatment modes on the physical and chemical properties of the wood pulp product and the strength properties of the resulting board materials is considered.
Modeling and Testing of Fluidic Flexible Matrix Composite Lead–Lag Dampers
Authors: Krott Matthew J. , Smith Edward C. , Rahn Christopher D.
Published: January 2020

A new lead–lag damper concept using a fluidic flexible matrix composite (F2MC) tube is presented in this paper. A model is developed for an articulated rotor blade integrated with an F2MC damper consisting of an F2MC tube, an inertia track, an
orifice, and a hydraulic accumulator. Benchtop tests using a 4.5-ft rotor blade demonstrate the performance of a smallscale F2MC damper. The blade–damper system model predictions are verified by comparing experimentally measured and model-predicted frequency response data.
In benchtop tests, the model predicts blade damping ratios of up to 0.34 with the F2MC damper. A simplified articulated blade based on the UH-60 rotor is simulated to assess the feasibility of a full-scale F2MC damper. Simulation results predict that the damper can generate
blade damping ratios of over 0.30 at low blade lag angles.
Lesion location agreement between prostatic multiparametric magnetic resonance, cognitive fusion biopsy and radical prostatectomy piece
Authors: Lourenço Mario , Pissarra Pedro , E Brito Duarte Vieira , Eliseu Miguel , Peralta Joao Pedro , Figueiredo Arnaldo , Marques Cristina
Published: January 2020

Introduction: Prostatic multiparametric magnetic resonance (mpMRI) allows for guided prostate biopsy (PB).Objective: To evaluate localization agreement between mpMRI lesions and histology obtained by cognitive PB and radical prostatectomy (RP) surgical specimen (SS). Methods: Out of 115 consecutive cognitive biopsied patients, 37 with positive PB were studied. Sample was characterized regarding age, prostatic volume, PI-RADS, location of lesion on mpMRI, lesion dimension, total number of fragments obtain by PB, number of fragments directed to the lesion, number of fragments with prostatic adenocarcinoma (PCa) and ISUP classification. The relationship between mpMRI and SS piece was analysed in 15 patients who underwent RP. Results: Regarding agreement between mpMRI and PB, agreement of location was observed in 26 (70.3%); 7 (18.9%) presented PCa positive fragments in the suspected zone plus others in the same lobe; 3 (8.1%) in the suspected zone plus the contralateral lobe and 1 (2.7%) had no PCa in the suspected zone but had bilateral PCa. The total number of fragments with PCa was lower in cases with agreement between mpMRI and PB (p < 0.05). Regarding agreement between mpMRI and SS, 5 cases (33.3%) presented the same location as described by mpMRI, 5 (33.3%) showed ipsilateral lesions in other zones of the prostate; 4 (26.7%) presented extensive bilateral lesions on all prostate zones and 1 (6.7%) showed previously unknown contralateral lesions. None of the factors studied related mpMRI and RP (p > 0.05). Conclusions: Localization agreement of mpMRI vs PB and mpMRI vs SS was present in 26/37 (70.3%) and 5/15 (33.3%), respectively. That suggests the existence of other lesions (multifocality) not identified on mpMRI.
Is Fast Track protocol a safe tool to reduce hospitalization time after radical cystectomy with ileal urinary diversion? Initial results from a single high-volume centre
Authors: Romagnoli Daniele , Schiavina Riccardo , Bianchi Lorenzo , Borghesi Marco , Chessa Francesco , Mineo Bianchi Federico , Angiolini Andrea , Casablanca Carlo , Giampaoli Marco , Corsi Paolo , D'Agostino Daniele , Brunocilla Eugenio , Porreca Angelo
Published: January 2020

Introduction and aim: Radical Cystectomy (RC) with ileal urinary diversion is one of the most complex urological surgical procedure, and many Fast Track (FT) protocols have been described to reduce hospitalization, without increasing postoperatory complications. We present the one-year results of a dedicated protocol developed at a high volume centre. Materials and methods: The FT protocol was designed after a review of the literature and a multidisciplinary collegiate discussion, and it was applied to patients scheduled to open RC with intestinal urinary diversion. To validate its feasibility, we compared its results with data collected from a 1:1 matched population of patients who had undergone the same surgical procedure, without the implementation of the FT protocol. Results: We enrolled in the FT group 11 (55%) patients scheduled to RC with ileal conduit diversion, and 9 patients (45%) scheduled to orthotopic neobladder (Studer) substitution, while a numerically equivalent population was enrolled in the control group, matched according to age at surgery, BMI, gender, ASA score, CCI, preoperative stage and type of urinary diversion. No statistically significant difference was found in terms of pre-operatory and intra-operatory domains. Median overall age was 71 years (Inter Quartile Range - IQR: 63-76) and mean operatory time was 276 ± 57 minutes. Hospitalization time was significantly reduced in the FT group, considering oralization and canalization items we found a significant advantage in the FT group. No statistically significant difference was found in the control of the post-operatory pain. We found no difference, in terms of both early and late complications ratio, among the two populations. Complications graded Clavien ≥ 3 were found in 4 patients of the control group (20%), while in only one patient (5%) in the Fast Track group, though this difference was not statistically significant. Conclusions: The Fast Track protocol developed in this study has proven to be effective in significantly reducing hospitalization time in patients submitted to RC with intestinal urinary diversion, without increasing post-operatory complications ratio.