bluuebunny/crossref_metadata_2025 huggingface dataset:
VVV Survey of Blue Horizontal Branch Stars in the Bulge–Halo Transition Region of the Milky Way
Authors: Montenegro Katherine , Minniti Dante , Alonso-García Javier , Hempel Maren , Saito Roberto K. , Beers Timothy C. , Brown David
Published: February 2019

We characterize the population of blue horizontal branch (BHB) stars in the bulge–halo transition region of the Milky Way using the VISTA Variables in the Vía Láctea (VVV) ESO Public Survey data. The selection of BHB stars is made using the globular cluster M22 as a reference standard and constructing color–magnitude and color–color diagrams with specific cuts in the ZYJHK

s
near-infrared (IR) passbands. A total of 12,554 BHB stars were detected, in a region within −10.°0 ≤ ℓ ≤ 10.°2 and −10.°2 ≤ b ≤ −8.°0. We provide accurate coordinates and near-IR photometry for this sample of BHB stars. We searched for overdensities of stars with sizes similar to those of known globular clusters and stellar streams. By comparing real data with Monte Carlo simulations, we conclude that the few overdensities detected are of low significance. We also constructed K

s
-band light curves for the BHB stars to study their variability. Taking an average of 52 epochs to calculate periods and amplitudes, we identify hundreds of candidate eclipsing binaries and a dozen pulsating stars. Finally, we made some comparisons with results obtained in a previous study for RR Lyrae variable stars in this same region.
Galactic Rotation and the Oort Constants in the Solar Vicinity
Authors: Li Chengdong , Zhao Gang , Yang Chengqun
Published: February 2019

Gaia DR2 data are used to calculate the Oort constants and derive the Galactic rotational properties in this work. We choose the solar vicinity stars with a “clean” sample within 500 pc. The Oort constants are then fitted through the relation between the proper motions as a function of Galactic longitude l. A maximum likelihood method is adopted to obtain the Oort constants and the uncertainties are produced by a Markov Chain Monte Carlo technique with the sample. Our results for the Oort constants are A = 15.1 ± 0.1 km s−1 kpc−1, B = −13.4 ± 0.1 km s−1 kpc−1, C = −2.7 ± 0.1 km s−1 kpc−1, and K = −1.7 ± 0.2 km s−1 kpc−1 respectively. The nonzero values of C and K represent a nonaxisymmetric model for the Galaxy. According to our results, the angular velocity

and the circular velocity decreases in solar vicinity. The local radial velocity also decreases along the radial direction due to C + K being negative.
A recent record of Romanogobio antipai (Actinopterygii, Cyprinidae, Gobioninae) from the Danube River in Bulgaria
Authors: Bogutskaya Nina G. , Stefanov Tihomir , Naseka Alexander M. , Diripasko Oleg A.
Published: February 2019

The Danube delta gudgeon, Romanogobioantipai, has been considered to be extinct because there were no reliable recent observations. The latest record confirmed by a voucher specimen dating from 1992. We report here on a specimen of R.antipai collected in 2016 in the Bulgarian sector of the Danube main stream using a bottom drift net at a depth of 8 m. The species determination is supported by morphological examination including discriminant and cluster analyses in comparison with three syntypes and five non-type specimens of R.antipai, samples of the R.kesslerii species complex and R.vladykovi. Romanogobioantipai most clearly differs from both R.kesslerii and R.vladykovi by proportional measurements (caudal peduncle depth, head width, eye horizontal diameter, and interorbital width), from R.kesslerii also by the number of scales above and below the lateral line (6 and 4, respectively, (vs. commonly 5 and 3), and from R.vladykovi, also by 8½ branched dorsal-fin rays (vs. 7½) and the vertebral caudal region longer than the abdominal vertebral region (abdominal+caudal vertebrae 19+21 or 20+21, vs. commonly 20+20 or variants with a caudal region shorter than the abdominal one). The possibility that R.antipai represents a deep-water cophenotype of either R.kesslerii or R.vladykovi, cannot be excluded. The new record demonstrates that R.antipai is still extant in the lower Danube but may be restricted to greater depths in the main channel and the deltaic branches.
A multi-objective imperialist competitive algorithm (MOICA) for finding motifs in DNA sequences
Authors: Gohardani Saeed Alirezanejad ,   Department of Applied Mathematics, Faculty of Mathematical Science, University of Guilan, Rasht, Iran, Bagherian Mehri , Vaziri Hamidreza ,   Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran
Published: February 2019

Motif discovery problem (MDP) is one of the well-known problems in biology which tries to find the transcription factor binding site (TFBS) in DNA sequences. In one aspect, there is not enough biological knowledge on motif sites and on the other side, the problem is NP-hard. Thus, there is not an efficient procedure capable of finding motifs in every dataset. Some algorithms use exhaustive search, which is very time-consuming for large-scale datasets. On the other side, metaheuristic procedures seem to be a good selection for finding a motif quickly that at least has some acceptable biological properties. Most of the previous methods model the problem as a single objective optimization problem; however, considering multi-objectives for modeling the problem leads to improvements in the quality of obtained motifs. Some multi-objective optimization models for MDP have tried to maximize three objectives simultaneously: Motif length, support, and similarity. In this study, the multi-objective Imperialist Competition Algorithm (ICA) is adopted for this problem as an approximation algorithm. ICA is able to simulate more exploration along the solution space, so avoids trapping into local optima. So, it promises to obtain good solutions in a reasonable time. Experimental results show that our method produces good solutions compared to well-known algorithms in the literature, according to computational and biological indicators.
Wisdom Tooth's Revenge: Retropharyngeal Abscess and Mediastinitis after Molar Tooth Extraction
Authors: Ucisik-Keser F. Eymen , Bonfante-Mejia Eliana E. , Ocazionez-Trujillo Daniel , Chua Steven S.
Published: February 2019

Retropharyngeal abscess is potentially associated with high morbidity and mortality as a result of its direct anatomical connection with the mediastinum. Therefore, knowledge of the relevant anatomy is essential for recognizing the presence and extent of disease in a timely manner. In this case report, we aim to review the pertinent anatomy and patterns of spread of infection from a full blown deep neck space infection to result in mediastinitis and empyema.
La construction en mélèze dans les Alpes du Sud depuis le xe siècle : une nouvelle lecture dendrochronologique de l’occupation humaine en montagne et des ressources forestières, données et méthodologies inédites
Authors: Shindo Lisa , Labbas Vincent , Édouard Jean-Louis , Guibal Frédéric
Published: February 2019

Dans les Alpes françaises du sud (Haute et Moyenne
Durance et massif du Mercantour), le petit patrimoine bâti, également
appelé vernaculaire, est étudié depuis une vingtaine d’années par les
dendrochronologues d’Aix-en-Provence. 110 structures bâties en
élévation (fermes et granges principalement), situées entre 790 et
2 090 m d’altitude, ont livré 1 331 pièces de mélèze, dont les
carottes et sections ont été datées par dendrochronologie. Sept
grandes phases de construction ont été identifiées, de la fin xiie-début xiiie siècle à la première moitié du xxe siècle. Mais des
mélèzes (essence la plus fréquemment rencontrée) ont été abattus à
presque toutes les époques ce qui témoigne d’une activité à la fois
d’entretien, de réparation, et de transformation permanente de ces
structures bâties. Le diamètre moyen des pièces de bois utilisées et
l’âge moyen des arbres au moment de leur abattage caractérisent la
ressource mobilisée au moment de son exploitation par les populations
humaines.
Dans la chaleur des fours : que restituer des pratiques des céramistes des sociétés anciennes ?
Authors: Frerebeau Nicolas , Pernot Michel
Published: February 2019

Véritables lieux communs dans l’étude de la
production des matériaux céramiques, la température et l’atmosphère de
cuisson sont pourtant des indicateurs ambigus lorsqu’il s’agit de
décrire la tache stratégique de constitue l’étape de la cuisson.
Malgré les problèmes – tant d’ordre méthodologique que conceptuel –
soulevés par les rares études antérieures, comment expliquer qu’ils
soient d’un usage si commun et, surtout, participent-ils effectivement
à la description de procédés techniques ?
Will Blockchain Bring an End to Corruption?
Authors: Kim Kibum , Kang Taewon
Published: February 2019

Blockchain technology is an electronic ledger of digital records that is distributed over a network of computers rather than located on single or multiple servers. As the technology is by itself transparent and secure even without a trusted third party involvement, many applications are being developed as a means of eliminating corruption around the world. This article examines how the blockchain technology could be used to curb corruption and take integrity to higher standards at a firm level, within-country level and cross-country level. Possible risks and challenges related to the technology were identified and found that without considering the data governance and security issues, the blockchain technology may not always lead to a socio-economic benefit.
Effect of Cerium and Lanthanum Additives on the Phase Composition of the Copper-Nickel Alloys
Authors: Samoilova O.V. , Trofimov Evgeny A. , Vakhitova E.R.
Published: February 2019

An experimental study of the phase composition for nine samples of the Cu–Ni–Ce–La alloys with different content of components was carried out. The nickel concentration in the experimental samples varies from 3 to 40 wt. %, the sum of cerium and lanthanum concentrations was not exceed 7 wt. %. Alloys samples of the system Cu–Ni–Ce–La were studied using scanning electron microscopy and microprobe analysis, as well as X-ray analysis. Also, Vickers micro hardness was measured on the cross sections of the experimental samples. In this work, the conditions of intermetallic compounds formation in the as-cast samples were studied. The results of the work can be used for the technological processes analysis of copper and copper-based alloys production.
Assessment of the Structural State of the Amorphous Alloys Thin Surface Layers
Authors: Kanunnikova Olga M. , Goncharov O.Yu. , Ladyanov V.I.
Published: February 2019

The complex approach based on the combination of methods of equilibrium thermodynamics and x-ray electron spectroscopy for layer-by-layer analysis of the composition of surface layers of amorphous alloys is described on the example of Fe-Si-B-Nb-Cu alloy.
The Poly-Substituted M-Type Hexaferrite Crystals Growth
Authors: Zaitseva O.V. , Vinnik D.A. , Trofimov Evgeny A.
Published: February 2019

In the presented article the possibility analysis of highly entropic oxide phases composition and structure formation was performed. Moreover, the studies devoted to the production of substituted single crystals with the M-type hexa-ferrite structure were carried out. The experiments were conducted to studying the possibility of obtaining oxide high-entropy crystalline solid solutions with the M-type hexa-ferrites structure. As the result of the crystallized samples investigation, the microcrystalline highly entropic Ba (Fe,Mn,Ni,Ti,Al)12O19 and (Ba,Pb,Sr)(Fe,Mn,Ti,Ni,Al)12O19 phases appearing was detected. Based on the obtained data, it is possible to consider that the poly-substituted crystals growth with M-type hexa-ferrite structure. The structural stabilization is promoted by high values of the configurational entropy of the crystal matrix components mixing.
Ni-Fe Alloys as Perspective Materials for Highly Efficient Magnetostatic Shielding
Authors: Solobai A.A. , Trukhanov A.V. , Grabchikov S.S.
Published: February 2019

Magnetostatic shields, based on Ni-Fe alloys, were obtained via electrochemistry method with different thickness of partial magnetic layers. The experimental researches of the magnetic properties and magnetostatic shielding effectiveness of the single-layer and malty-layer cylindrical sample of the shields, based on the electrodeposited Ni80Fe20and Ni50Fe50alloy, are carried out. It has been shown that the shields of gradient type (200 μm Ni50Fe50+200 μm Ni80Fe20and 100 μm Ni50Fe50+300 μm Ni80Fe20), containing layers with different values of saturation induction (Bs), have a higher shielding efficiency than shields of symmetric type (400 μm Ni50Fe50and 400 μm Ni80Fe20). Maximum efficiency of magnetostatic shielding has been noted for 200 μm Ni50Fe50+ 200 μm Ni80Fe20sample. It opens wide prospects for practical application for protection of the microelectronics devices against permanent magnetic fields.
Austenite to Ferrite Transformation Kinetics in Fe-9 %Cr Alloys - I. General Kinetic Analysis
Authors: Mirzaev D.A. , Okishev K.Yu. , Mirzoev A.A. , Makovetskii A.N.
Published: February 2019

The paper considers theoretical aspects of the kinetics of austenite → ferrite transformation in an Fe–9 %Cr alloy, a common model of diffusionless transformation. In previous studies it was shown that this transformation under isothermal conditions shows a behaviour typical for nucleation site saturation, including the change of the Avrami exponentn(determined as the slow of transformation curve on double logarithmic scale) from 4 to 1. Activation energies determined in two ways: by the ‘nose’ temperature of the normal C-curve and by the slope of the C-curve re-drawn on a reverse temperature scale are unexpectedly similar (272–315 kJ/mole) and not temperature-dependent. But the complete TTT diagrams calculated using these values determined directly from experimental data and the precise formula of Cahn’s solution of grain face nucleated transformation problem do not provide good agreement with experiment in the whole temperature range. This may mean that the theory of site saturation needs some correction.
The Usage of Hydroextrusion for Plastic Deformation of Magnetostrictive Iron-Gallium Alloys
Authors: Gervasyeva I.V. , Milyutin V.A. , Davidov D.I. , Khlebnikova Yulia V.
Published: February 2019

For the first time hydroextrusion process was chosen for Fe-Ga ingots deformation with a gallium content of 19 and 20 at.%. The samples were annealed at 950oC, followed by air cooling. Structure of deformation and primary recrystallyzation were investigated by the method of electron back-scattered diffraction (EBSD). The degree of hydroextrusion deformation achieved was 28 – 42 %. There was not found any crystallographic texture at such degree of deformation. The value of magnetostriction in recrystallization sample was about 100 ppm. Available in literature methods and approaches to creation of the Fe-Ga samples from the point of view of receiving high magnetostriction and also a possibility of machining of the samples are discussed.
Analysis of the External Conditions Affecting on the Cavitation Resistance of a Steel
Authors: Alwan Hussam L. , Lezhnin N. , Korobov Yury
Published: February 2019

The aim of this study is to analyze the effect of cavitation erosion test conditions on the surface resistance of medium carbon steel. The ultrasonic vibratory specimen system was used to perform the experiments under the laboratory conditions. The vibratory frequency and the displacement amplitude were 20 kHz and 20 μm, respectively. In design of experiments, four various cavitation behaviors have been studied based on four cavitation test conditions corresponding to those behaviors. These conditions can be summarized as follows: (1) the usage of water as a testing liquid; (2) replacement the water with 3.5% NaCl solution; (3) applying a certain voltage to cause a combined electrochemical action working simultaneously with the water; and (4) applying the same voltage by using the 3.5% NaCl solution instead of water. The obtained results showed that the mass loss differs by test modes applied.
Regression Model of TCLE of Low Melting Glass of System MgSO4-KPO3-Na2B4O7
Authors: Stolbovsky A.V. , Farafontova Elena , Vyatchina Vita
Published: February 2019

A second-order regression polynomial model is offered, taking into account a pair components interaction for TCLE calculation of low-melting glasses in system MgSO4-KPO3-Na2B4O7. The analysis of the obtained model is carried out. The results adequacy, obtained by modeling in comparison with the experimental data, is shown. It is established that the square pair interaction of the MgSO4-KPO3and MgSO4-Na2B4O7components, when modeling this system, can be neglected.
Numerical and Experimental Investigation of the Heat Treated Steel Part Microstructure and Hardness
Authors: Maisuradze Mikhail V. , Kuklina Alexandra A.
Published: February 2019

The approach for coupled experimental and numerical estimation of the heat treated steel part microstructure and hardness is presented. The method is based on the investigation of the austenite transformation in a steel during continuous cooling, Jominy hardenability test and numerical modeling of a quenching process. The presented approach is verified by estimation of the 20CrMo5 steel gear shaft microstructure and hardness. The estimated results are in good agreement with the experimental ones.
Development of Capillary Tube Production Technology
Authors: Yur'ev Boris , Dudko Vyacheslav
Published: February 2019

A manufacturing process was developed using an electric through-type furnace for capillary tubes used for single-use injection syringes. The process flow diagram consisting of a number of sequential steps and tube heat treatment conditions in protective atmosphere of pure hydrogen providing also for the tube purging with inert gas were considered. The electric furnace installed capacity and heating element dimensions were found as a result of the thermotechnical calculations. Industry research was carried out with a view to optimize the annealing process of capillary tubes in the electric furnace. A choice of material for the muffle fabrication was justified. Temperature fields inside the muffles were evaluated. The optimal flow of protective gas and the maximum allowable flow of purging gas in the form of nitrogen and argon were determined. Mechanical properties were studied for tubes (stocks), welded at the medical goods fabrication plant in Tumen and fabricated at the Pervouralsky Novotrubny Plant. Test data were obtained for optimal rates of tube movement in the furnace, allowing production of capillary tubes, acceptable for medical needle fabrication after annealing. It was demonstrated that capillary tube heat treatment, ensuring the required condition of both outside and inside surfaces, as well as required mechanical properties, is possible with the use of nitrogen as protective (instead of hydrogen) and purging gases. At that probability of better tube surface condition significantly grows.
Technology and Equipment for Plasma Electric Arc Granulation of Fused Welding Flux
Authors: Artemov Arseny O. , Naumov Stanislav V. , Ignatov Michael N.
Published: February 2019

The article outlines the main principles of granulation technology for fused welding flux using highly concentrated heat sources (e.g. plasma arc). Modern plasma equipment and methods of its use for producing new welding materials (plasma-granulated welding flux) from mineral raw materials and synthetic mineral alloys are described. The developed technology makes it possible to produce granulated flux in a wide range of fractional composition (from 0.2 to 3 mm). Studies have focused on the influence of granulation regimes (plasmatron moving speed, current, voltage, arc length) on formation process and the morphology of welding flux particles. Mineral raw materials used for granulation were igneous rocks (basalt, hornblendite) and synthetic mineral alloys. The results obtained during experiments on the use of highly concentrated heat sources for granulation of a fused welding flux confirm the feasibility and prospects of this technology. Typical equipment for air-plasma cutting is used, and no new complex technological equipment is required, therefore it eliminates large material and labor costs.
The Analysis of the Influence of Manufacturing Practice of Anode Paste on its Consumption
Authors: Belousova Olga V. , Kostina Ksenia V.
Published: February 2019

The article is devoted to the study of the impact of technological features of the anode paste production on one of the technical-and-economic indices – its consumption. It is shown that the prior thermal preparation significantly affects the quality characteristics of pitch and petroleum cokes. The comparison of pitches of foreign and homeland producers revealed the advantage of the last because of their small ash content and the lowered content of sodium. Granulometric composition of the dry mix is determined on the basis of different coke brands. They are close to the concentrations of fractions regulated by the technology of production of the anode paste. The conducted semi-industrial tests were in accordance with the laboratory studies and confirmed the fact of reducing the consumption of the anode paste when using the petroleum coke as a filler.
The Time and Heat Dependence of the Nitrogen Distribution upon Steel Alloying with Nitrided Manganese
Authors: Smirnov Leonid A. , Zayakin Oleg V.
Published: February 2019

In this article the time and heat dependence of the nitrogen distribution upon steel alloying of 04Cr20Ni6Mn11Mo2NVNb steel grade by the nitrided manganese of Mn85N10 grade at the holding in the air atmosphere from 2 to 30 minutes in the temperature range 1450-1550 °С was experimentally determined. It was determined that the highest degree of nitrogen transition into steel is 99% and is observed with a short holding time of 2 min (after the introduction of nitrided manganese into the steel melt) in the low-temperature region ~ 1450 °С. Further holding and / or temperature growth results in the release of nitrogen in the gaseous form, due to the thermal dissociation of the nitrogen-containing compounds contained in the melt and removal of nitrogen from the melt into the gas phase, which leads to a decrease in the degree of nitrogen transition to the steel. The key possibility for obtaining a steel of the indicated grades group with a nitrogen content of 0.45-0.6% is shown when alloying in an air atmosphere in a low-temperature region (1450-1500°C), while optimizing the holding time.
Non-Equilibrium Crystallization of a Eutectic Alloy - Mathematical Model
Authors: Drozin Alexander D. , Dudorov Maxim V. , Yaparova Natalia M.
Published: February 2019

The process of a eutectic alloy crystallization is considered when the eutectic alloy is instantly cooled from the liquid state to below the eutectic transformation temperature. The features of such crystallization are considered. The mathematical model of the process is constructed that takes into account the nucleation of new phases particles, their growth and the associated change the concentrations of the melt components. The nuclei of new phases are supposed be spherical. As they grow, they come into contact and become lamellar. The developed approach was applied to the amorphization process of the eutectic alloys. An amorphous state has been reached if the clusters of solid phases can’t grow above nanosize. The model allows researching the necessary amorphization conditions.
New Possibilities of ESR for Modern Machine Engineering
Authors: Levkov Leonid , Shurygin Dmitry , Kisselman Mikhail
Published: February 2019

Electro-slag re-melting (ESR) is a process that combines all important elements of steel melting conversion. JSC “RPA “CNIITMASH” continuously developed ways to use ESR to manufacture critically important parts for power engineering, including nuclear power engineering, heavy-duty machine engineering and other machine building industries. Enhanced performance of product is an important competitive advantage that ESR provides in comparison to other metallurgical processes. Present report reflects results of the latest research work aimed at resolving issues related to control and management of refining and crystallization processes, cost reduction for ESR products. Practical relevance of developed approach to control of ESR metal quality is revealed by data of achieved parameters which characterize properties of pipes and pipeline elements in energy and nuclear power industries which rely on ESR ingots as work-piece blanks.
Iron Oxidation State Analysis in ESR Slag
Authors: Levkov Leonid , Pankratov Denis , Shurygin Dmitry
Published: February 2019

It is shown that the value of the equilibrium oxygen partial pressure,Po2as a value available for measurements is possible to be taken as a measure of slag redox potential of, taking into account its electronic system performance. Application of the electromotive force method (EMF) allowed establishing the character of a change in the average oxidation state of iron νFedepending onPo2, the temperature and slag composition. The study of Mössbauer absorption spectra of quenched slag samples confirmed the possibility of simultaneous presence of iron in the flux in oxidation states from 0 to +3.
Research on the Thermal Work of the Drum-Type Chamber Furnace with a Constant Temperature of the Working Space
Authors: Cheremiskina Nadezhda , Loshkarev Nikolay , Lavrov Vladislav
Published: February 2019

In the report the scheme and features of thermal work of the chamber furnace of drum type for heating of metal products under hardening are presented. The technical characteristics of the furnace, some results of thermal calculation are shown. Computer simulation of gas motion and heat exchange processes in the furnace are presented. The study was performed using CAE-system (CAE, Computer aided Engineering) – software module ANSYS Fluent. Boundary conditions of flow flow flow were set in this module. To verify the convergence of the calculations, the control of the current values and calculated temperature residuals was used. The simulation results are presented graphically and contain a visualization of the temperature and velocity distribution fields, as well as a vector distribution of gas flow velocities. The obtained results of computer simulation allowed to estimate the efficiency of thermal and gas-dynamic work of the developed design of the chamber drum-type furnace with a constant temperature of the working space. The developed design of the furnace for heating metal billets with the movement of billets in the furnace on the drum allows to solve some problems of resource and energy saving, can also be used for heat treatment of bars, pipes, strips, and rolled bars of various shapes.
Development Features of Thermal and Gas-Dynamic Performance of Mineral Wool Cupola Furnace
Authors: Matyukhin V.I. , Zhuravlev S.Ya. , Khandoshka A.V.
Published: February 2019

Major unit for mineral melt production in industry is a shaft (cupola) furnace. Such type units are noted for the ease of fabrication and maintenance, high melting rate (up to 100-150 t/m2 per day), as well as high heat utilization efficiency (up to 60-80 % of the total supply). Design disadvantages may include inefficient workspace side-view, poor thermal and gas dynamic performance, lack of practical methods to impact the melting process. Another pressing problem is related to melt production in the amount of no more than 3 t/h, with the average coke consumption of up to 24-270 kg/t, and the overheating temperature level of no more than 1350-1400 °С. Thermal and gas dynamic performance analysis of mineral wool cupola furnace, based on evaluation of zone balance model demonstrated that mineral melt is produced under conditions of essential nonuniformity of the bed temperature, gas phase composition and heat exchange conditions, both throughout the bed height and the unit cross section.
Survey of Methods of Refining Catalysts for the Extraction of Platinum Group Metals
Authors: Devyatykh E.A. , Devyatykh T.O. , Boyarsky A.N.
Published: February 2019

Currently, about 80% of all industrial chemical reactions are carried out with the help of catalysts or depend on catalytic processes. In this case, catalysts containing platinum group metals (hereinafter - PGM) occupy a special position, due to their high catalytic activity and selectivity. A significant part of the net global demand for PGM is for the production of catalysts, accounting for approximately 45% for platinum, 30% for palladium, 92% for rhodium, 35% for ruthenium, 15% for iridium. The most important condition for the economical use of catalysts containing precious metals is their efficient recycling, which will be discussed below.
Studying Kinetics of Arsenic Recovery from Copper Dross by Alkaline Sulfide Leaching
Authors: Nabiyeva A.A. , Kulenova N.A. , Mamyachenkov S.V.
Published: February 2019

Copper dross are produced by rough decopperizing of blast furnace lead bullion. During liquation separation of copper dross from lead bullion most of arsenic and copper are concentrated in copper dross, arsenic content is approximately 4% As. Currently the processes for arsenic recovery from copper dross are understudied. In this work the focus is given to studying kinetics of the process for recovering arsenic from copper dross by alkaline-sulfide leaching. Alkaline sulfide leaching allows carrying out selective removal of arsenic into solution, keeping at this non-ferrous and precious metals in leaching residue. The studied method of alkaline sulfide leaching of copper dross provides backgrounds for developing technology that would allow processing of copper dross with selective arsenic removal from lead production cycle. By minimizing circulation of this harmful impurity in lead production it is possible to lessen destructive effect of its aggressive compounds on smelting-units refractory. Kinetics of alkaline sulfide leaching of copper dross was understudied up to date. This work is an attempt to fill the gap.
Quality Increase in the Gold-Containing Cathode Sediment
Authors: Zhmurova Viktoria V. , Nemchinova Nina V. , Vasilyev Andrey A.
Published: February 2019

The cathode sediments (CS), obtained as a result of industrial processing of gold-polymetallic raw material with complex chemical and mineral composition, contain a significant amount of impurity metals (copper, lead, zinc, iron, etc.), which leads to a significant increase in the cost of subsequent refining of these materials. The authors carried out experimental work on preliminary acid treatment of CS for the purpose of leaching impurities and increasing the share of precious metals in them. The objects of research were cathodic sediments (bypass solutions of the enterprise) containing copper and lead in the amount,% wt., respectively: 21.29 and 4.11. We tested nitric acid as a solvent in laboratory tests. For the selection of optimal leaching parameters, studies were carried out at various concentrations of the agent (from 50 to 350 kg/m3) and the ratio of L:S - (3-7):1. The duration of the experiments was 2 h, the experiments were carried out with vigorous stirring and standard ambient temperature (25°C). The experimental data processing was carried out with the help of STATISTICA 6.0 software; As factors of variation, we chose: concentration of acid, ratio of liquid and solid phases. It has been determined that nitric acid provides effective purification of CS from impurities. After the chemical enrichment, the content of precious metals in leaching cakes increased, the CS became compliant with the requirements of TU 117-2-3-78. When processing cathode sediments with nitric acid, 99% of silver passes into solution, which then allows it to be recovered from solutions by cementation and, consequently, to obtain alloys of gold and silver separately.
Theory of Copper-Electrolyte Slimes Decoppering in the Presence of Hydrogen Peroxide
Authors: Lobanov V.G. , Naumov K.D. , Korolev A.A.
Published: February 2019

The problem of copper leaching from copper-electrolyte slimes is discussed. To intensify the long and costly process, it is proposed to use a leaching system containing sulfuric acid and hydrogen peroxide as an oxidizing agent. The chemical transformations possible variants at the treatment of slime under the specified conditions and the thermodynamic parameters of the predicted reactions are considered. Solution composition effect on the copper dissolution rate at room temperature was studied in the presence of hydrogen peroxide using the rotating disc technique. It is found that dissolution rate constant at using hydrogen peroxide slightly inferior to dissolution rate constant under autoclaved conditions in an oxygen atmosphere.
Forecasting the Structure and the Hindered Contraction of Casts by Using the ProCAST System of Engineering Analysis
Authors: Erdakov Ivan Nikolaevich , Ivanov Vasily A. , Vyboishchik Alexander V.
Published: February 2019

The paper presents the methods for forecasting the structure and geometrical parameters of casts by using the ProCAST system of engineering analysis. Based on experimental studies and computer simulation, a regularity between the supercooling rate of aluminium alloy on the one hand and the nucleation rates and crystal growth rates on the other has been established. There have also been established dependencies describing the change in the plasticity modulus, the coefficient of thermal linear expansion, Poisson's coefficient within the temperature range of 20 to 1000°C for cores made from α-set mixture. The computer simulation based on the experimental data of the processing of silumin casts made it possible to forecast the alloy structure with the probability level of 95%, and to calculate the accuracy of hindered contraction of the alloy with accuracy equal to ± 1.5%.
Shot Blasting of the Cemented Gear Parts
Authors: Shveyova T.V. , Astashchenko V.I. , Shveyov A.I.
Published: February 2019

Properties of parts after a shot-blasting of a surface are investigated. Change of size of compression stresses in a surface layer of the cemented tempered parts processed by different compositions of materials in shot blasting units is shown. After shot jetting peening of parts increase in a limit of endurance for 40 – 60% is reached. The maximum effect at a shot jetting peening of toothed parts is reached when using for a shot blasting of the mix consisting of steel chopped fraction and glass balls.
Investigation of the Flanging Process for the Parts with High Conical Angles
Authors: Demyanenko E.G. , Popov I.P.
Published: February 2019

In this paper the new method of forming based on flanging is investigated. The obtained experimental results supported the theoretical conclusions and allowed us to define geometric dimensions of a blank for forming the thin axisymmetric parts with minimal thickness fluctuations. This analysis serves as a foundation for further design of the technological process.
Fuel Pipes Coil Drawing Line Production for Diesel Engines
Authors: Antimonov Aleksey , Pushkareva Nadezhda
Published: February 2019

The technology and equipment for diesel engines steel fuel pipes cold rolling and coil drawing production on a self-aligning mandrel are considered. We presented current production line scheme for the pipes production, which includes pipe-rolling drum mills, radial forging machines, thermal furnaces with a protective atmosphere, finishing lines for unwinding coils and straightening pipes, a system of conveyors and stores for transferring coils from one unit to another. A list of articles and patents containing basic information on this topic is attached.
Surface Pressure Treatment of Titanium Alloy Bars by Transverse Rolling
Authors: Antimonov Aleksey , Pushkareva Nadezhda
Published: February 2019

The results of the process experimental studies of titanium alloys transverse rolling bars are presented. The efficiency of using such a process for reducing the surface roughness is shown. The samples were tested after rolling on corrosion-resistance resistance, ultrasonic testing, and also the study of the metal microstructure was made. For the bars transverse rolling in industrial conditions, a tooling was developed and created, intended for installation on operating centerless lathes instead of tooling with a cutting tool. Production tests of new equipment has shown its good performance.
Numerical Analysis and Simulation of the Straightening Process of Heavy Rails on a Horizontal Roller-Straightening Machine
Authors: Timakov E.V. , Dubinskiy F.S.
Published: February 2019

In this paper, the ABAQUS is adopted to carry on numerical simulation on straightening process of R65 heavy rail. The straightening process has been simulated here using the FE package of ABAQUS. All the input data were extracted from experimental tests according to tail manufacturing. Moreover, initial camber of the rail was measured after hot rolling and cooling process.
Development of a Method of Forging Long-Length Blanks with Intensification of Shear Deformation
Authors: Volkov Vladimir P. , Salikhyanov Denis Rinatovich , Kamantsev Ivan S. , Shamshiev Aziret A.
Published: February 2019

Modern press forging manufacture of large steel forgings is moving along the way of increasing service properties and reducing energy-power parameters. This is evidenced by a significant number of works devoted to the study of forging technology with the use of special tools allowing to implement severe plastic deformation. As a result, it is possible to improve significantly the metal structure at the same values of the forge reduction. The paper presents the results of the development and investigation of a new method of forging large steel billets with the intensification of shear deformation and with the use of standard anvils. The analysis of the stress-strain state in comparison with traditional forging scheme on an example of forging billets made of high speed steel R6М5 (State Standard GOST 19265-73) is presented. It is shown that the accumulated degree of shear deformation, as well as the uniformity of its distribution, is higher for the new method with the same reduction values. Approbation of the new method of forging on a hydraulic press was carried out for the blanks made of aluminium alloy D16 (State Standard GOST 21488-97).
Development and Optimization of Flat Products Manufacturing at Rolling Mill 3200
Authors: Kurpe Oleksandr H. , Kukhar Volodymyr V.
Published: February 2019

In this work the developing manufacturing technology for 4mm thick plates produced of 220mm thick continuous cast slabs instead of 150mm thick slabs for mill 3200 (Metinvest Trametal SpA) is shown. The technology has been developed with the mathematical model of the rolling process. Тhe rolling technology for manufacturing of plates (4×3125×16000mm) from slabs (217×1355×780mm) has been developed. The developed technology makes it possible to reach the final rolling temperature of 826oС, which provides a good opportunity to use it for plate production in keeping with the hot, normalizing, controlled rolling technology or TMCP, and does not limit the existing grade mix. It is possible to use for production of 220mm thick slabs instead of 150mm thick slabs.
Analysis of Thermal Stresses in Layered Composite AD1 + Cr20Ni80 + M1 after Heat Treatment
Authors: Shmorgun Victor Georgievich , Bogdanov Artem I. , Taube Alexander O.
Published: February 2019

The results of modeling of the influence of layers thickness of the Ni-Cr-Al composite on value of thermal stresses on its interlayer boundaries after diffusion annealing are presented. It is shown that the cooling of the AD1-Cr20Ni80 composite after annealing, which provides formation of a DZ at its interlayer boundary, consisting of three interlayers (CrAl7, NiAl3 + CrAl7 and Ni2Al3 + CrAl7), leads to spontaneous separation of the aluminum layer,due to the action of tensile stresses, exceeding the zone strength of the interlayer boundaries (CrAl7) - (NiAl3 + CrAl7), and at k> 0.3 - (NiAl3 + CrAl7) - (Ni2Al3 + CrAl7) with the ratio of layers thickness of aluminum and the alloy Cr20Ni80 - k <0.3, which leads to the formation of layered Cr20Ni80 / ( Ni2Al3 + CrAl7) / (NiAl3 + CrAl7) or Cr20Ni80 / (Ni2Al3 + CrAl7) coatings.
Studies on Technological Features of Obtaining Thin Bimetallic Brass-Aluminum-Brass Strips
Authors: Pellenen Anatole , Kareva Nadezhda T. , Ivanov Vasily A.
Published: February 2019

Manufacturing of bimetallic brass-aluminum-brass strips is connected with a number of technological features. The features under consideration are cladding (welding) of the primary components, annealing of metal compositions and strain modes assignment. The purpose of the studies upon the development of bimetallic brass-aluminum-brass strips production technologies in SUSU is to analyze the modes, as well as to elaborate recommendations for the primary components thickness selection, strain modes assignment and annealing using bell-type furnace and strand-type furnace. The performed studies resulted in recommendations dealing with annealing cycles. The studies have also delivered the regression ratio between the thickness selection of primary components during the cladding operation, and the supreme total strain. A correct ratio prevents from the surface ruptures on the bimetallic brass-aluminum-brass strips surface while rolling.
Influence of Deformation Conditions on the Power Regimes of the Process of Cold Crimping of a Pipe Billet in a Conical Die
Authors: Udalov Andrey A. , Udalov Aleksander V. , Parshin Sergey V.
Published: February 2019

An engineering technique has been developed that makes it possible to determine the power regimes of the process of crimping a tubular billet in a conical die, taking into account the effect of deformation conditions. The influence of the geometric parameters of the workpiece and tool, the crimping coefficient and non-contact deformation on the axial stress of the crimping process is studied. The main factors influencing the limiting values ​​of the workpiece crimping factor are established. Calculations are performed for the crimping process performed on an open circuit (without stop block), taking into account the friction and hardening of the material. The obtained results are in good agreement with the known experimental data and can be used in the development of the processes of crimping of pipe billets.
Studies of Influence of Process Parameters on the Strain Rate at High-Speed Wire Drawing
Authors: Radionova Ludmila V. , Shirokov Viacheslav V. , Faizov Sergei R. , Zhludov Maxim A.
Published: February 2019

This article presents the results of the effect of drawing speed on the strain rate and resistance to plastic deformation. The wire drawing on modern high speed wire drawing machines significantly increases the required amount of drawing dies. The influence of the technological parameters: speed drawing, half-angle of the die, wire diameter and a single strain on the rate of deformation of the metal. The influence of the technological parameters: speed drawing, half-angle of the die, wire diameter and a single strain on the rate of deformation of the metal. It is found that increasing the resistance to drawing dies and achieve passport velocities drawing, when selecting process parameters drawing guided by the principle of uniform strain over the cross section of the wire by matching the single strain with half-angle dies and friction coefficient on the formula given in the article.
Management of Rolls Handling Facilities of Long Products Shop
Authors: Kinzin D.I. , Levandovskiy S.A. , Soloveva Natalya S.
Published: February 2019

The existing problems of rolls handling facilities, as in the case of PJSC "Magnitogorsk Iron and Steel Works" Long products shop were considered in terms of a proposition to have them solved by means of introduction of an automated information system for accounting and management. A review of literary sources on issues of information technology, management, logistics and organization of rolls handling facilities was performed. The basic provisions of automated information system have been developed, and the issue of rolls handling facilities management on its basis is considered.
Texture Evolution during Hot Deformation of Al-Cu-Li-Mg-Zn-Zr-Sc Alloy
Authors: Erisov Yaroslav A. , Grechnikov Fedor V. , Kuzin Alexandr , Bobrovskij Igor N.
Published: February 2019

The Gleeble-3800 unit was used to simulate physically the upsetting of cast and hot rolled semi-finished products from aluminum-lithium alloy V-1461 over the temperature range of 400-460°C and the strain rates of 1-60 s-1. Following texture analysis of upset samples showed the most typical preferred crystallographic orientations and its formation features depending on the temperature-strain rate schedules. The formation of recrystallization type orientations at a strain rate of 60 s-1 is a distinctive feature of the cast samples’ behavior during deformation. In general, the established regularities of texture formation allow to produce a hot-rolled semi-finished products from V-1461 alloy with a given structure’s crystallography in compliance with requirements for blank’s forming and product’s operation.
Calculation of Modes of Arc Welding under the Flux of Double-Sided Butt Joints
Authors: Sidorov Vladimir P.
Published: February 2019

This paper gives the analysis of energy costs for arc automatic welding under the flux of double-sided butt joint without edge preparation according to the thickness of welding sheets. The coefficients for a linear dependence of specific energy from plate thickness are obtained. From this, a calculation method of effective power, current and arc voltage is proposed according to the joint formation speed. To calculate a fusion area of a weld section, a model of a surficial normal-circular heat source with an average heat flow in a heating spot 14−16 kW/cm2is used. Acceptable convergence of target and experimental cross-section areas of a weld is achieved for an arc reverse polarity. Calculation method let take into account the influence of arc polarity on a fusion area of a base metal. Main efficiency factors of a double-sided welding are defined. Possible reasons of augmentation of fusion effectiveness of a base metal in comparison with the electrode metal are noted.
Properties Anisotropy of Additive Manufactured High-Porous Titanium Alloy with Non-Equiaxial Cellular Structure
Authors: Loginov Yuri N. , Stepanov Stepan I. , Grekhov S.K.
Published: February 2019

Numeric simulation of compression test was carried out for a high-porous structure of a titanium alloy produced by additive manufacturing method with non-equiaxial performance of pore cells. The stress-strain state of a cellular titanium alloy with diamond-shaped unit cells was determined by the finite element method (FEM) in ABAQUS software for the plane formulation of the problem. The distribution of stresses, as well as the modulus of elasticity of the cellular material, was proved to depend on the loading direction.
CORD BLOOD PLATELET LYSATE: IN VITRO EVALUATION TO SUPPORT THE USE IN REGENERATIVE MEDICINE.
Authors: Teofili Luciana
Published: February 2019

Platelet-rich plasma (PRP) is an inexpensive and safe substitute of recombinant growth factors in Vitro and in vivo. Due to its putative effect on tissue repair, the use of autologous PRP has become largely popular. Recently, a jellified PRP derivative obtained from umbilical cord blood (CB) has been utilized in vivo to treat mucosal and cutaneous lesions. Nevertheless, whether PRP derived from CB and adult blood display different potency in promoting cell growth in Vitro has been rarely investigated. In this study, we compared cytokine profile and mesenchymal cell growth supporting the ability of platelet lysate obtained from adult and cord blood. Our in vitro results strongly back the utilization of CB platelet lysate in vivo, as an efficacious, safe and inexpensive alternative to promote damaged tissue healing when the autologous PRP is contraindicated. Moreover, the policy of manufacturing CB platelet lysate can limit the current disposal of many collected CB units not suitable for transplant due to their low nucleated cell count.