bluuebunny/crossref_metadata_2025 huggingface dataset:
Unusual Presentation of Fibrous Dysplasia in an Elderly Patient
Authors: Alkhaibary Ali , Alassiri Ali H. , Alsalman Mohammed , Edrees Sabig
Published: February 2019

Fibrous Dysplasia is a benign fibro-osseous lesion occurring throughout the skeletal system with a predilection for craniofacial bones, long bones, and ribs. Fibrous dysplasia develops during bone formation and growth with a variable natural evolution. It is considered a genetic nonheritable disease resulting from missense mutations that occur postzygotically in the GNAS1 gene. This mutation leads to a focal congenital failure of proper bone formation and arrest at the woven bone stage. In turn, this leads to a decreased mechanical strength, causing bone pain, pathological fractures, and skeletal deformities. Besides clinical examination, fibrous dysplasia is diagnosed based on the results of radiographic imaging and the microscopic histopathological findings. On CT scan, fibrous dysplasia shows the characteristic "Ground-glass" appearance with well-defined borders. On MRI, fibrous dysplasia has a low signal intensity on T1-weighted MRI and variable signal intensity on T2-weighted MRI. We hereby report a case of an unusual presentation of fibrous dysplasia in a 67-year-old female presenting to the emergency department with generalized malaise and lower limb pain. Fibrous dysplasia may present in the elderly population and can be difficult to differentiate from other malignant and benign lesions affecting the skeletal system.
Identifier et enregistrer des vestiges archéologiques sous couvert forestier à partir de données LiDAR : méthode et limites
Authors: Chevigny Emmanuel , Saligny Laure , Granjon Ludovic , Goguey Dominique , Cordier Alexandra , Pautrat Yves , Giosa Alain
Published: February 2019

Depuis plus de dix ans, des recherches sur les
ensembles de structures en pierre sous forêt sont menées dans la forêt
du Châtillonnais (Côte-d’Or, France). Les prospections réalisées
jusqu’à ce jour consistaient en un relevé GNSS systématique des
structures. Ces prospections ont été complétées en 2012 par une
acquisition LiDAR sur 400 km² réalisée par Parcs Nationaux de France
(PNF). Cet article a pour objectif de présenter la démarche développée
au sein du projet, pour traiter et enregistrer les données
archéologiques détectées par le LiDAR. L’enjeu de celle-ci est
d’harmoniser la saisie et les modalités d’enregistrement des
structures identifiées (à partir des jeux d’images dérivées des
données LiDAR) par les différents chercheurs. Pour la mise en place de
cette méthode, un test de vectorisation a été réalisé sur un même
secteur par huit chercheurs afin d’identifier les biais de
vectorisation puis de proposer un processus méthodologique associant
les indices de visualisation utilisés, la nature des vestiges à
détecter et leur implantation topographique et des techniques
d’enregistrement (base de données spatiales, outils de vectorisation,
etc.) connectées aux méthodes de relevés de terrain.
Appréhender le stock de métal monnayé au ive siècle après J.-C.
Authors: Guihard Pierre-Marie , Blanchet Guillaume , Bocquet-Liénard Anne , Angélique Jean-Claude , Liénard Étienne , Bataillé Marie-Paule , Dupré Juliette , Gabriel Jean-Louis
Published: February 2019

Parmi les thématiques
abordées en numismatique à l’aide de l’archéométrie, les recherches
spécifiques sur le stock de métal monnayé au ive siècle s’avèrent fascinantes mais
délicates. Afflux de nouvelles ressources métalliques, refontes
volontaires de monnaies : tous ces phénomènes sont de grande
conséquence pour les monnayages produits dans les différents ateliers
de l’Empire romain tardif. Certaines données de ce type sont
mesurables. Les alliages métalliques (donc ici monétaires) contiennent
en effet des éléments mineurs ou en traces, constituant la « carte
d’identité » de l’approvisionnement des ateliers monétaires. Il y a 10
ans Isabelle Bollard et Jean-Noël Barrandon réunissaient plusieurs
analyses de monnaies en alliage cuivreux émises au cours du ive siècle. Nos propres
observations, obtenues dans le cadre d’un projet de recherche financé
par la région Normandie (intitulé FANUM), sur 14 528 monnaies (nummi) de la
période constantinienne contenues dans un trésor découvert
fortuitement à Saint-Germain-de-Varreville (Manche), nous ont incités
à reprendre, de façon plus approfondie, l’étude des alliages utilisés
au cours de cette période, en portant notamment notre attention sur
les teneurs en or et en argent. En effet, la grande variété des
ateliers représentés au sein du trésor favorisait idéalement une telle
enquête. Le choix de la fluorescence X portable a permis d’élaborer un
protocole d’analyse précis et adapté à un grand nombre de monnaies.
L’exploitation de 774 analyses réalisées sur des nummi frappés dans les ateliers
occidentaux a permis de compléter les travaux antérieurs, mais
également de mettre en évidence l’utilisation de stocks métalliques
différents à partir des années 320.
HYBRID TECHNIQUE FOR ECG SIGNAL COMPRESSION USING PARALLEL AND CASCADE METHOD
Authors: Surekha K. S. , Patil B. P.
Published: February 2019

The recording of electrical activity of the heart by using electrodes is known as electrocardiography (ECG). In long time monitoring of ECG, a huge amount of data needs to be handled. To handle the situation, an efficient compression technique which can retain the clinically important features of ECG signal is required. The continuous monitoring of this signal requires a large amount of memory. Hence, there is a requirement of compression. The compression of ECG signal using transforms in cascade is explored to incorporate the added advantages of both the transforms. This paper presents compression of ECG signal by hybrid technique consisting of cascade and parallel combination of discrete cosine transform (DCT) and discrete wavelet transform (DWT). The simulation is carried out using MATLAB tool. Various wavelet transforms are used for the testing purpose. The performance measures used are Percent square mean Root Difference (PRD) and CR to validate the results. The methodology using cascade combination proved to be better than the parallel technique in terms of Compression Ratio (CR). The highest CR achieved is 28.2 in the method using DCT and DWT in cascade. Different DWTs are used for the testing purpose. The parallel method shows the improved PRD as compared to the cascade method.
Mapping Game Mechanics for Learning in a Serious Game for the Energy Transition
Authors: Ampatzidou Cristina , Gugerell Katharina
Published: February 2019

The integration of learning goals with game mechanics in serious games used in urban and spatial planning processes has the potential to enable game designers and planners to create games with narratives tightly aligned to particular processes and lead to increased learning outcomes. This study presents the results from testing Energy Safari, a serious game for the energy transition in the province of Groningen, and empirically associates specific game mechanics with learning events, derived from players' reports. The research is based on the analysis of post-play questionnaires. Play-testing Energy Safari illustrates that different learning events can be triggered by the same game mechanics, an observation which can be applied in serious game design to facilitate players with different learning needs and styles. In addition, play testing to evaluate the learning performance of serious games should be integrated in the game design process. However, to achieve lasting learning and actionable knowledge, serious games should be used complementarily with other civic participation methods.
Participatory E-Planning With Civic Crowdfunding
Authors: Goodspeed Robert
Published: February 2019

Civic crowdfunding, or recruiting participants and collecting financial donations online for local development projects with public benefits, is an increasingly popular method for participatory e-Planning at the neighborhood scale. However, little is known about the donors' backgrounds, project involvement, or social capital outcomes. This article reports on a survey of 154 donors to ten such projects that finds that they are geographically diverse, are older and whiter than the project tracts, report some volunteering activities, and experience modest changes to social capital outcomes. The article discusses implications of the findings, such as how practitioners can ensure inclusion of diverse people and encourages participation among donors, and what future research is needed.
Research of Polyethylene in Products of Autocomponents
Authors: Shafigullin Lenar N. , Romanova Natalia V. , Gabdrakhmanov Azat T.
Published: February 2019

Polyethylene is widely used in the production of products for the automotive industry, due to the unique properties and the possibility of manufacturing hollow products of complex geometry. In this work the thermal research of polyethylene in finished productsand the quality assessment of autocomponents materials, depending on the type of polyethylene were conducted. An assessment methodologyof the material of products is suggested, which indicates the difference between the batches of autocomponents products for the acceptance or rejection thisbatch by conducting DSC-analysis. It was found that the products of autocomponents, in particular, "splash-absorbing shield", based on LDPE with a melting point above 110 °C have unsatisfactory performance characteristics. It is shown that modifying additives to improve the elasticity of the LDPE lead to partial the amorphization of PE, that is, a decrease in the degree of crystallinity by 4% relative to the LDPE without additives.
Investigation of NiO-Al2O3-SiO2 Properties via XRD, FTIR Techniques and Thermal Analysis
Authors: Antoshkina Elizaveta , Rakova Olga , Efremov Andrey
Published: February 2019

Nowadays, nanostructures made on the basis of mixed oxides are of great interest for fundamental scientific and applied researches because of its potential applications, such as photo catalysts, luminophores, sensitive elements of gas sensors and vacuum sensors. The article describes nanostructural properties of NiO–Al2O3–SiO2 prepared by sol-gel method. Nanocomposites were obtained by mixing a solution of Si (OC2H5)4 (TEOS) as a SiO2 precursor with a solution containing Al (NO3)3 · 9H2O and Ni (NO3)2 · 6H2O. Ethanol was used as solvent. The gel was dried at room temperature and annealed in the 100–500 °C range. The behavior of chemical bonds is considered by using FTIR technique. Crystallization of NiO phase at 500 °C is observed in XRD patterns. Aluminum atoms are incorporated into silica matrix, which was confirmed by XRD. The amorphous structures which are desirable for next generations are formed at room temperature.
Effect of Explosive Processing on the Structure and Properties of Polyarylate
Authors: Adamenko Nina A. , Agafonova Galina V. , Kazurov Andrej V.
Published: February 2019

Polyarylate (PA, polyoxybenzoyl) is a heat-resistant linear aromatic polyester with a high degree of crystallinity, high physicomechanical and tribotechnical properties that is limited in the possibilities of processing into products. The polymer has low deformability and fluidity in the range of softening temperatures, as well as narrow temperature processing intervals, limited by the destruction temperatures. A promising way to obtain compacts from PA is explosive processing, which ensures the simultaneous realization of high pressure (up to 10 GPa) and temperature (up to 1000 °C). Comparative results of morphology, crystalline and chemical structure and thermomechanical properties of polyarylate after static pressing (SP) and explosive processing (EP) are presented. It was found that EP at the pressure of 2.8 GP, which excludes the destruction and decomposition of polymer compacts, does not cause significant changes to its phase composition, crystalline and chemical structure. The monolithic compacts obtained by EP have higher thermostability and heat deflection temperature than statically compressed ones.
Optimization of the Composition and Structure of Deformable Heat Resistant Aluminum Alloy
Authors: Toleuova Ainagul , Balbekova Bakhyt , Erakhtina Irina
Published: February 2019

The necessity of finding scientifically grounded methods for the development of new heat-resistant, wear-resistant and corrosion-resistant aluminum alloys is presented in the present work. For this purpose, the analysis of modern methods for computer calculation of phase diagrams in multicomponent metal systems using the Thermo-Calc program was carried out. Therefore, a quantitative analysis of the phase diagram the Al-Cu-Mn-Zr system was carried out, as the basis of deformable high-temperature aluminum alloys. Isothermal and polythermal sections of the phase diagram were calculated in this system. The temperatures of phase transformations were calculated. The mass and volume fractions of the phases in the studied alloys were calculated. The range of concentrations and temperatures at which the maximum amount of dispersoids Al20Cu2Mn3may be achieved, was defined. The minimum amount of Al2Cu phase is calculated, which should correspond to the best heat resistance of alloys. It is substantiated that in the alloys of a new generation of ALTEK type, the use of homogenization and quenching operations is inexpedient, which implies the possibility of a significant reduction in the cost of heat treatment in comparison with industrial alloys, such as 1201.
Thermodynamic Modeling of the Processes of Interaction of Calcium, Magnesium, Aluminum and Boron with Oxygen in Metallic Melts
Authors: Mikhailov Gennady G. , Makrovets L.A.
Published: February 2019

A method for calculation of the diagrams of steel deoxidation and modification by calcium, magnesium, aluminum and boron was developed. The coordinates of the liquidus surfaces of the oxide systems B2O3–Al2O3–MgO, B2O3–Al2O3–CaO, B2O3–MgO–CaO were found at 1873 K. The energy parameters were determined for the theory of subregular ionic solutions of the studied oxide systems. The coordinates of the solubility surfaces for the systems Fe–Mg–Al–B–O, Fe–Ca–Al–B–O, Fe–Mg–Ca–Al–B–O were calculated. The effect of the total pressure on solubility of magnesium and calcium in liquid iron was studied. The activity of the components of the metallic melt was calculated using the first-order interaction parameters (Wagner's theory). The activities of the components of solid solutions (oxides and spinels) were equated with their molar fractions. It was shown that during extensive refining of metal from the oxygen, only a small fraction of boron oxidizes and these oxides form fraction of the oxide melts. The major non-metallic oxide inclusions were magnesia spinel, calcium bialuminate and liquid oxide formations. The "free" boron was dissolved in liquid metal in amounts which were in equilibrium with oxide phases.
Doping Titanium Dioxide by Fluoride Ion
Authors: Fedorov Sergei N. , Bazhin Vladimir Yuryevich , Povarov Vladimir G.
Published: February 2019

Titanium dioxide has a special feature: anatase, to rutile transformation which was considered in our investigations. It is especially important to keep anatase form of titanium dioxide for photocatalytic materials, different ceramics with tribo-chemical properties, self-cleaning coatings and self-sterilizing coatings. For that only one of the titanium dioxide forms is more suitable – anatase, which is more active but not stable, because it transforms to rutile during the time or with the temperature increase loses its activity. Different methods of stabilising anatase have been considered in the paper. Several doping agents have been determined and it was chosen fluorine ion to modify titanium dioxide. Stabilization of anatase is achieved by preparing the reaction mixture by a sol-gel method with hydrofluoric acid. It has shown thermodynamic data, results of experiment, temperatures of anatase to rutile transformation of non-doped and doped titanium dioxide, its X-Ray diffraction and TGA. It is proved that titanium dioxide doped by fluorine ion keeps anatase form till the temperature is more than 1000 °C.
Investigation of Physical and Chemical Processes of Formation of Composite Materials with Specified Structural Phase Characteristics
Authors: Mikhailov Gennady G. , Morozova A.G. , Bamburov Vitalii G.
Published: February 2019

In domestic practice development of the production technology of rail grinding wheels has outstripped the development of technology for the production of zirconium electro-corundum; the electrocorundum meets the requirements of non-thermal metal treatment. Among the artificial abrasives the leading place belongs to corundum and corundum based alloys (zirconium electrocorundum). At the moment the domestic factories of the abrasive industry are producing zirconium electrocorundum of the pre-eutectic composition (containing about 25% of zirconium dioxide) for rough grinding applied for the rough processing of the rolled products. The zirconium electrocorundum for the final non-thermal metal treatment is not produced by domestic factories; there are no technical requirements for such a material. This work was targeted to develop compositions and parameters for melting of prototypes for the industrial scale production of zirconium electrocorundum with specified and controlled properties. The grain of zirconium electrocorundum in the grinding wheels used in rail grinding trains has specific properties. According to the principles of non-thermal material processing, the structural and phase state of the grinding grain should provide high strength and durability under normal conditions, and at the same time it should tend to shear during the thermal exposure. The design of domestic electrocorundum for rail grinding with properties which are not inferior in comparison with the imported analogues is a strategic issue.
Features of Technological Materials Application in Thermal Manufacturing
Authors: Mukhametzyanova G.F. , Zapadnova N.N. , Zapadnova E.A.
Published: February 2019

Widely used in thermal production quenching surroundings, gas atmospheres and working mixtures for shot peening are considered. Features of materials at their use are presented and recommendations for more effective application are given. The change of quenching surroundings cooling capacity on the water-soluble polymer basis after an annual operation is shown. Hardening oils during operation are exposed to oxidation and viscosity index change, what affects on the quenched products properties. For endothermic atmospheres that are used in the parts chemical-thermal treatment the composition improvements are required. Working mixtures for shot peening must have a certain composition, properties and sizes, depending on the tasks to be solved.
Influence of the Glassfiber Filaments Distribution on Quality and Performance of Hole Processing on Printboards
Authors: Shulgin Aleksey N. , Dyakonov Aleksandr A. , Gorodkova Anastasia E.
Published: February 2019

The description of the basic material for the printboards production is given, its basic physical properties are formulated, the features of machining are shown and the range of problems that arise in this case is determined. We specified common mistakes that could lead to mass marriage in the manufacture of printboard assemblies. The structure and composition of base materials for the production of clad dielectric materials are described in this paper. An equation for calculating the maximum shear stress for a composite material is given. It is shown that nesting and, as a consequence, an increased content of glass fibers through a chain of interrelated factors affects the quality and reliability of the printboard operation and the entire product as a whole. In addition, the dense laying of fibers increases the cutting tool wear significantly. The article provides the technique of the base material choice depending on the distribution structure of glassfiber filaments on which the labor productivity, the quality, the cutter power and the manufacturing cost of the printboards depends.
Solution to Technological Problems of Raising the Reliability and Quality of Castings Based on Titanium Alloys
Authors: Shcherbakova Galina I. , Varfolomeev Maxim S. , Storozhenko Pavel A.
Published: February 2019

We consider the problems of the complex application of the aluminium-yttrium binder in the fabrication of high-temperature resistant melting crucibles and investment molds thermoschemically resistant to titanium melts. The results of the contact interaction investigations of a molten titanium alloy with a material of aluminum-yttrium ceramics are presented. The usage of ceramic products of α-Al2O3–Y3Al5O12∙α-Al2O3 composition under conditions of high-temperature melting and pouring under vacuum minimizes the physicochemical interaction and significantly reduces the alpha case layer on cast products, thereby improving their operational properties.
Experimental Study of Strain-Softening Stage in Materials
Authors: Mironov Vladimir I. , Lukashuk Olga A. , Kamantsev Ivan S.
Published: February 2019

Physical theory of reliability is based on research into degradation processes of various origins which take place in a material of a stressed construction. Experimental evaluation of parameters carried out for such processes is a practically important problem by itself. One of the approaches to solving this problem is related to the studies into the stage of material softening due to deformation. This paper analyzes the issues of experimental validation of material softening properties in terms of a phenomenological approach to the problem of structural fracture. Results of deformation analysis for the “machine – model specimen” system, using catastrophe theory are used to form requirements for carrying out experiments which investigate the softening stage of materials. The success of such experiments – which should include recording a branch descending to zero on a computer diagram – is possible when small specimen, made from structurally heterogeneous materials, are strained in a sufficiently rigid testing machine. Thus, the conditions for manifestation of the softening stage connect properties of the material with properties of the load-applying system. Therefore, the material's limiting state – preceding the fractured – also depends on the conditions of loading, and the criteria of that fracture would be nonlocal. In consideration of the results of diagrams plotted from various bases for deformation measurement, a necessity of utilizing local material characteristics for calculation purposes is discussed. As an example of using the complete diagrams for determining kinetics of material degradation from external load, the results of specimen testing, which follows a cyclic training, are cited.
Particle Size Distribution and Structural State Analysis of Mechanically Milled Strontium Hexaferrite
Authors: Egorov Ivan N. , Egorova Svetlana I. , Kryzhanovsky Viktor P.
Published: February 2019

Article presents an experimental study result of milling coarse strontium hexaferrite in beater mill with formation of magneto fluidized bed and without it. Magneto fluidized bed is formed by mutually perpendicular constant and alternating gradient magnetic fields. We studied the dynamics of particle size distribution from milling time and parameters of magnetic fields. Microstructure dynamics of strontium hexaferrite powder particles milled in various regimes was studied by X-ray diffraction methods. Milling efficiency and energy efficiency of milling process were studied in conditions with and without powder fluidization by magnetic fields. Analysis of experimental data showed advantages of milling in magneto fluidized bed in increased efficiency, particle size distribution homogeneity and powder chemical activity because of lattice micro-stresses.
Effect of Micro-Alloying with Boron and Niobium on Properties of Cr-Mn-Mo Steels
Authors: Gervas'ev Michail A. , Sharapova Valentina A. , Berdnikov Aleksey A.
Published: February 2019

Economically alloyed steels for critical details of drill pipes have been studied. Effect of microalloying on structure and properties has been investigated. The article shows that boron and niobium additives change the structure and properties of Cr-Mn-Mo steels after quenching and high tempering. Methods of optical and electron microscopy have been used. Basic mechanical properties and impact strength of investigated steels are determined. Optical and electronic fractography has been carried out. The quantitative content of the ductile component is determined in steel fracture. It is shown that steel microalloying leads to a substantial structure refinement. This is due to the influence of niobium on the austenite grain value. An increase in the amount of carbide particles leads to structure refinement with an increased molybdenum content. Boron microadditives allow obtaining the tempered martensite structure throughout the product section. This provides an increase in both the strength and ductile properties. Combined microalloying of chromium-manganese-molybdenum steel with additions of boron up to 0.005 % and niobium up to 0.05 % makes it possible to increase the strength and reduce the tendency to brittle fractures significantly. The nature of the fracture becomes completely ductile. Distinct cleavage fracture surface feature “river patterns” are observed in unmodified steels. Сleavage facetes are large enough, it proves the presence of large grains in the steel. Microalloying changes the destruction mechanism, it becomes a ductile “dimple rupture”. An increase in the molybdenum content to 0.6 % makes it possible to obtain strength above 1100 MPa in microalloyed steel.
Experimental Studies of Wear Resistance of Anti-Friction Coatings of Bimetal Fluid-Film Bearings
Authors: Rodichev A.Yu. , Babin Alexander , Gorin Andrey
Published: February 2019

The paper presents experimental results of wear resistance measurements of anti-friction coatings of bimetal fluid-film bearings. As a result, nature and peculiarities of wear process of anti-friction coatings and steel base have been identified. An analysis of antifriction properties of studied copper-based coatings is presented. The paper also features recommendations for application of the studied coatings obtained by means of gas-flame spraying.
Effect of Mesostructural Elements on Radiation-Induced Porosity in 16Cr-19Ni-2Mo-2Mn-Nb-Ti-V-P-B Austenitic Steel
Authors: Pastukhov Vladimir I. , Portnykh Irina A. , Lobanov Mikhail L.
Published: February 2019

Different mesostructural elements of 16Cr-19Ni-2Mo-2Mn-Nb-Ti-B austenitic steel have been examined after neutron irradiation to damage dose up to 82 dpa by scanning electron microscopy using orientation microscopy (EBSD). Radiation porosity with maximum void size up to 200 nm was observed in austenitic steel structure after neutron irradiation. Nonuniformity, related to mesostructural elements, such as general grain boundaries, special CSL boundaries Σ3 (twins), areas with high density of low-angle boundaries, is typical for radiation porosity.
Improving the Durability of Machine Parts Using a Combined Method
Authors: Yakovleva A.P.
Published: February 2019

A combined processing method for improving the performance features of machine parts (durability), that works under intense wear and high lubricated or boundary friction has been developed; a working installation based on a CNC lathe has been developed. The research on resulting surface hardness material of steels: С45Е; 1.1191 (1 option); SA-240 TP 310S (2 option); 34CrNiMo6, 36CrNiMo4, 40NiCrMo4KD (3 option) and hardening depth variation under different combined processing conditions has been carried out. Surface roughness parameters have been calculated. The suggested method can increase the operational life of a machine part due to improving features, such as surface hardening, creating a favorable surface topography.
Effect of Boron on the Microstructure and Mechanical Properties of Low-Carbon Tube Steel
Authors: Babenko Anatoly A. , Zhuchkov Vladimir I. , Selmenskih Natalia I.
Published: February 2019

Effects of boron in low-carbon tube steel grade 17G1SU on nonmetallic inclusions, structure and mechanical properties were investigated. Experimental samples of rolled metal containing boron 0.006 and 0.011% are characterized by predominantly small, nonmetallic inclusions not more than 5 μm, which are represented by complex alumomagnesium spinels in the shell of manganese and calcium sulfides, and small silicate inclusions. Nonmetallic inclusions of comparative pipe steel sample, containing no boron characterized by the presence of larger inclusions presented complex oxysulfide and sulfide films. The main structural component of the comparative and experimental samples is ferrite. The introduction of boron is contributed by a decrease in the average size of ferritic grains from 8.7 μm (0% B) to 6.2 (0.006% B). Increasing the boron content to 0.011% leads to slight increase (up to 6.8 microns) of the size. The mechanical properties of 10 μm rolled metal pipe steel ensured the production of rolled products of strength class X80 without additional (thermal) treatment, as a result of the reduction in the size and shape of nonmetallic inclusions, and formation of dispersed structure.
Promising Directions for the Stabilization of Ferroalloy Production Slags
Authors: Zayakin Oleg V. , Kel' Ilia N.
Published: February 2019

In this paper the analysis of the processes for spontaneous decay of slags from the production of refined ferroalloy grades is performed. It is shown that the main reason for the decay is the formation of a dicalcium silicate in highly basic melts with CaO / SiO2 ratio of 1.5-3.1. Based on the performed studies, three main promising directions for the stabilization of slags of ferroalloy production have been formed. First direction is the replacement of the calcium cation (or transformation) in a dicalcium silicate, for example, with the magnesium cation or the production of non-decaying compounds of the gehlenite type (2CaO·Al2O3·SiO2), mainly due to the application of phase composition peculiarities of the waste rock for ferroalloy raw materials. Second direction is the reduction of the dicalcium silicate content with a decrease in the ratio of CaO / SiO2 in the slag less than 1.4, due to the separation of the silicothermic reduction process into two stages, obtaining in the first stage a low-basic (CaO / SiO2 = 1.3-1.4) non-decaying tailing slag, and on the second one - highly basic return slag (1.8-1.9), which is used in the first stage of this technological chain. The third direction is the replacement of the SiO anion of dicalcium silicate with other anions, for example, ВО by means of small additions of calcium borate, colemanite, etc. A possibility for stabilization of ferroalloy production slags with obtaining of construction crushed stone corresponding to the requirements of TU 0798-69-00186499-2014 "Crushed stone and sand from ferroalloy slags. Technical conditions», is shown experimentally.
Тhe Study of the Process of Metal-Thermal Reduction of Boron from the Slag of the System CaO-SiO2-MgO-Al2O3-B2O3
Authors: Zhuchkov Vladimir I. , Salina V.A. , Sychev A.V.
Published: February 2019

The results of thermodynamic modeling of the effect of aluminum (0.005–0.1%), contained in the metal at constant silicon concentrations (0.2%) and carbon (0.1%) on the boron reduction process from the slag of the system CaO-SiO2-MgO-Al2O3-B2O3 basicity (CaO)/(SiO2) equal to 5 in the temperature range 1400–1700 °C, in steps of 50 °C are presented. For modeling, the software complex HSC Chemistry 6.12 developed by Outokumpu Research Oy (Finland) was used. The calculations using the Equilibrium Compositions module at a gas-phase pressure of 1 atm, containing 2.24 m3 of N2 (gas) as a neutral additive were performed. The obtained simulation results indicate the thermodynamic possibility of boron reduction from the slag of the CaO-SiO2-MgO-Al2O3-B2O3 system by silicon and aluminum, whose concentration in the metal is insignificant – 0.2 and 0.005–0.1%, respectively. It was found that an increase in the initial aluminum content in the steel promotes an increase in the concentration of reduced boron in the metal with a content of 4% B2O3 and a given temperature. Thus, at a process temperature of 1650 °C, an increase in the initial aluminum content from 0.005 to 0.1% made it possible to increase the boron concentration in the metal by 28.5%. The results of thermodynamic modeling characterizing the effect of temperature on the degree of boron reduction at different aluminum contents are presented. Experiments on the inter-phase distribution of boron between the slag of the CaO-SiO2-MgO-Al2O3-B2O3 system and the metal were carried out in a high-temperature Tamman resistance furnace. Low-carbon steel containing 0.005% Al was used. It was shown that aging of the metal under the slag containing 4.3% of B2O3 is accompanied by reduction of boron, the amount of which in the finished steel is 0.0089%. The coefficient of boron assimilation (KB) is 5.8%, which is in principle correlated with the results of thermodynamic modeling. The obtained results of thermodynamic modeling and experimental data showed that it is possible in principle to directly microlite boron steel by reducing it with aluminum and silicon contained in the metal.
Medium-Carbon Free-Cutting Steel
Authors: Ryabov A.V.
Published: February 2019

The paper presents theoretical and experimental studies of the formation processes of boron nitride, aluminium nitride, aluminium oxide and manganese sulphide inclusions in a free-cutting steel. Fact Sage software was used to model the behaviour of non-metallic inclusions. Formation temperatures and the amount of key inclusions in steel were calculated. Formation order of inclusions is as follows: aluminium oxide > boron nitride > manganese sulphide > aluminium nitride. The object of study was the A45AR grade steel in 1.1–1.2 kg ingots. It was melted in an induction furnace, and aluminium, nitrided ferrosilicon and ferroboron were added after deoxidation before tapping. Quality estimation included chemical composition, macro-and microstructure, the character and shape of non-metallic inclusions. The finished metal contained fine and uniformly distributed inclusions of boron nitride. Qualitative and quantitative analysis of boron nitrides distribution in metal matrix showed that they were present both as individual and complex compounds, mostly of spherical shape. The size of BN inclusions varied from 0.18 to 6.52 μm. The amount of boron added to steel did not affect the size of MnS non-metallic inclusions.
Improvement of Agglomeration Technology by a Sinter Mix Preheating
Authors: Shapovalov Alexey N. , Dema Roman , Kalugina Olga B.
Published: February 2019

A series of industrial experiments was carried out on the sinter machine No. 1 of the sinter department of JSC "Ural Steel". The dynamics of the sinter mix temperature during the technological stages of its preparation from pelleting to loading on pallets was studied, depending on a water temperature change during pelletizing. It was defined that for the winter working of the sinter department of JSC "Ural Steel" the water temperature increases, which supplied the pelletizer to moistening, for every 10 ° C, facilitates an increase in the temperature of the sinter mix on the pallets by 1.5-2.0 °C. Therefore, for stable sinter mix production with a temperature of more than 55 ° C, it is necessary to use water supplied to the pelletizer for moistening, with a temperature of at least 85°C. To implement the proposed technology, it is necessary to equip the sinter machines with water-heating recuperative heater, installed above the sintering machine behind the ignition hood and using heat, radiated from the surface of the sinter.
Mathematical Model of the Reduction of Metals from Complex Polymetallic Types of Ore Applicable to the Electron Mechanism
Authors: Gamov P.A. , Drozin Alexander D.
Published: February 2019

The mathematical description of the electron mechanism of reduction of metals from complex polymetallic types of ore has been suggested. The description of the mechanism was based on diffusion and thermal processes occurring in the phases of a reducing agent and an oxide, and chemical reactions on the surface of a phase boundary. The effect of the major physics-chemical parameters on the rate of formation and movement of the reducing vacancies was considered. The obtained model allows calculation of the process of metal reduction from the bulk of a complex oxide by using the approach of the electron mechanism, which considers the process of reduction not as the interaction of the reducing agent with molecule of the metal oxide, but as the interaction with the oxygen anion of a crystal lattice.
Nitric Acid Treatment of Olympiada Deposit Refractory Gold-Bearing Concentrate
Authors: Rusalev R.E. , Rogozhnikov Denis A. , Naboichenko Stanislav S.
Published: February 2019

This article covers acid nitric leaching of Olympiada deposit refractory gold-bearing concentrate after alkaline leaching of stibnite. Thermodynamic analysis of the reaction pyrite and arsenopyrite with nitric acid chemical equations was performed. Equilibrium Eh-pH Pourbaix diagrams of heterogeneous systems studied, containing iron and arsenic were charted. Investigation of elemental and species analyses was maintained. The analysis of the main elements distribution and their combining over grains with the help of electron-probe microanalysis (EPMA) was investigated. It is established, that the material mainly consists of compounds of quartz, dolomite and calcite, as well as pyrite and arsenopyrite. Pre-treatment decarbonization operation of the feed material was proposed with the aim to reduce nitric acid consumption. The dependences of effects of the nitric acid concentration and L/S ratio on iron and arsenic dissolving were determined.
Choice of Efficient Technology for Aged Enrichment Tailings Processing
Authors: Kozhonov Almaz , Maymanova Zheenayym , Kritskii Aleksei
Published: February 2019

The article is devoted to the development of an efficient technology for the processing of aged tailings of the «Solton-Sary» enrichment plant in Kyrgyzstan. Based on the detailed investigation of initial material, authors select most appropriate technology for processing of technogenic material, considering through gravity separation, flotation and hydrometallurgical methods of processing. The methods of sequential gravity separation/flotation scheme of enrichment and direct cyanidation of initial ore at different regimes are analyzed; advantages of aged tailings agitation leaching are established. Research, presented in the article, could be useful for enrichment plants, which are developing technologies of the waste products processing in order to increase the raw material base.
Sorption and Membrane Technologies for Mine Water Purification
Authors: Timofeev Konstantin L. , Kurdiumov Vasilii , Maltsev Gennady
Published: February 2019

The importance of the research is due to the lack of potable water (~1.6 million m3 per year) in a rapidly developing city in the Urals. One way to solve this problem is to purify water from the spent copper mine with a debit of ~4.4 million m3 of water per year. The most advanced techniques recently used for obtaining drinking water of a high quality are based on ion exchange and reverse osmosis, which can ensure an obtainment of water with initial contents of impurities much below the maximum permissible values. Based on the real experience the article compares sorption and membrane technologies in terms of water purification efficiency and cost of potable water production. The large-scale tests of mine water purification were carried out at sorption and reverse osmosis pilot plants with the capacity of 1 m3 per hour for the incoming flow. The source water had the following composition, mg/dm3: 0.5–0.9 Mn; 1.0–1.7 Ni; 80-140 Ca; 30-40 Na; 40-70 Mg; 0.2–0.6 Cu; 8.1–9.5 Si; 0.01–0.03 Zn; 0.01–1.70 Fe; <0.01 Al; < 0.005 As; < 0.005 Pb. At the same time the salinity was 640–680 mg/dm3, the water hardness was 9.5–11.5 mmol/dm3 and pH was 7.0-7.5. The content of non-mentioned impurities was below the detection limit. The resulting treated water met the requirements for the quality of potable water for both purification techniques. It was concluded, that the best option for treatment of mine water is ion exchange.
To the Question of Casting Alloys of Non-Ferrous Metals in the Metal Mold
Authors: Gavariev R.V. , Savin I.A. , Leushin I.O.
Published: February 2019

The article discusses the features of the casting process of non-ferrous metals, the basic properties of various alloys, affecting the appearance of various defects of the resulting casting. The proposals to improve the efficiency of the casting of non-ferrous metals in metal molds and specific recommendations for improving the performance properties of metal depending on the melt being poured are given.
Prospects of Using Titanium Dioxide as a Component of Modifying Composition for Aluminum Casting Alloys
Authors: Shlyaptseva A.D. , Petrov I.A. , Ryakhovskii A.P.
Published: February 2019

The authors studied the possibility of modifying aluminum-silicon alloys using titanium dioxide at standard melting temperatures up to 800 °C. The result is achieved due to the combined use of titanium dioxide and alkali and alkaline-earth metal fluorides. Calculations of the change in the Gibbs energy of chemical reactions of interaction of titanium dioxide with aluminum, cryolite, barium fluoride were carried out. The thermodynamic possibility of modifying silumin by the reduction of titanium from dioxide in the presence of additives selected was shown. Experimental melting was carried out and the results of mechanical tests of experimental alloys depending on the additives used were obtained. After melt treatment using the study combinations, the alloy structure becomes partially modified, which increases the mechanical properties of silumin.
Evaluating Heat Resistance of Mold Shells in Investment Casting
Authors: Kulakov B.A. , Dubrovin V.K. , Zaslavskaya O.M.
Published: February 2019

The paper describes the theory of developing the heat-resistance criterion for disposable ceramic molds exposed to poured metal, creating a computational and experimental method for computing the heat resistance by rapidly heating the mold by an electric arc, as well as analysis of comparative data on quartz, dinas, and electric-corundum molds from the standpoint of the developed criterial-evaluation theory. In this case, the heat resistance is of one-time character, as this mold sustains only a single casting. Computational and experimental data indicate a low heat resistance of β-quartz, making them non-recommendable for annealing and metal pouring if there is not supporting filler. Molds based on electric-corundum or dinas fillers are free of such drawbacks, with the latter being considerably cheaper. The use of tridymited dinas powders is effective after grinding the spent dinas lining of electric furnaces.
Application of Numerical Model of Continuous Cast Bloom Crystallization to Improve the Efficiency of Mechanical Soft Reduction Technology
Authors: Smyrnov Yevgen , Belevitin Vladimir , Skliar Vitalii
Published: February 2019

The paper presents the results of the analysis of thermal state of continuous cast bloom on the stage of incomplete crystallization in the area of possible places of application of technology of Mechanical Soft Reduction (MSR), received during simulation on mathematical model, which was implemented in the software package using the finite element method. For the conditions of continuous cast bloom with a cross section of 360-400 mm, we studied the characteristics of temperature change over the cross section of the bloom, the growth dynamics of the solid shell, the number of the solidified component, and the end point position of solidification depending on the technological parameters for continuous casting of A516, 5140 1070 and AISI steel brands. The obtained data on the thickness of the crystallized shell of continuous cast bloom and the amount of solid phase depending on the casting speed and steel grade allowed us to conclude about the possible place of installation of the MSR unit. The results of mathematical simulation can be transferred in a digital form to the strength model of deformation of continuous cast bloom at the stage of incomplete crystallization.
Model for Solidification of the Working Layer of the Roll in the Chill of the Centrifugal Machine
Authors: Vdovin Konstantin N. , Yachikov Igor M. , Danilyuk Kirill A.
Published: February 2019

The paper presents a mathematical model and the elements of a computer program for calculation and visualization of solidification of the rotating molten iron of the working layer of the roll in the centrifugal machine. We established the dynamics of changes in supply rate of carbide nanopowder feeding on the surface of the molten metal, provided its uniform distribution along the solidifying layer of the cast iron. It is shown that the working layer of the iron cools sideways and more intensively from the side of the chill mould; the areas, which are located near it, are the first to reach the solidus and liquidus temperatures. During cooling the layer of the iron, a maximum of temperatures is observed at a distance of 25 – 30 mm from the protective flux contacting surface. It was established that for a uniform distribution of nanopowder in the solidifying layer of the iron its feeding supply rate needs to be proportional to the speed of the moving the front of particle penetration, which is defined by the solidification front. Powder feeding needs to start from the time concurrent with the start of moving the front of particle penetration into the metal and to finish when an opposite crystallization front begins to form from the side of the flux.
Influence of the Intensity of Electromagnetic Mixing in Continuous Casting Machine Crystallizer on the Formation of Grade Blanks
Authors: Nuradinov A.S. , Saipova L.H-A. , Uzdieva N.S.
Published: February 2019

The influence of the electromagnetic mixing (EMM) of liquid metal in the mold of the continuous casting machine on its thermal work, the formation of the structure and properties of cast billets are investigated. The influence of the current and frequency of EMM on the mechanical properties, macro-and microstructure of round and square sorted billets was established.
Procedure for Evaluating Competitiveness of Production Processes
Authors: Petrov Igor , Kharitonov Veniamin , Polyakova Marina
Published: February 2019

At present time a lot of methods are used for the assessment of product quality level, as well as its manufacturing perspectives. Only quantitative data can be used in order to compare the competitiveness of products, facilities, companies, etc. But methods for quantitative assessment of technological processes competitiveness have not been still proposed. The present paper describes a developed procedure for evaluation the competitiveness of technological processes. It takes into consideration the main factors which are used for estimation of process effectiveness: quality of products, level of applied technologies and production costs. In order to range these parameters, it is proposed to use weighting factors for each of them. An integrated efficiency index may vary within a range of 0 to 1. This method allows not only evaluating competitiveness of production processes, but also choosing the most rational production process, based on required properties of the processed item. The application of the developed approach is shown on the example of reinforcing steel manufacturing, which can be produced in different ways. The obtained results of calculation present a comparison of selected manufacturing techniques by the following parameters: strength and ductility properties of reinforcing bars, an applied forming method, possibility of a layer winding and a range of diameters of bars in coils. It is shown that the developed model makes it possible to determine a trend in development or adjustment of operating parameters for existing options of processes applied at an operating plant.