bluuebunny/crossref_metadata_2025 huggingface dataset:
Floatability and calculated reactivity of sulfide minerals and gold
Authors: Ignatkina V. A. , Kayumov A. A. , Yergesheva N. D.
Published: January 2023

The paper provides the results of theoretical reactivity calculations for gold, molybdenum, stibnite, galena, chalcopyrite, arsenopyrite and pyrite in comparison with such experimental data as the floatability of monomineral fractions with butyl xanthate, wetting angle values, changes in the kinetics of the mineral electrode potential. The following calculation series in terms of reactivity and oxidizing ability were established by calculation: Au < Sb2S3 < MoS2 < PbS < CuFeS2 < FeAsS < FeS2. During the Hallimond tube flotation, natural gold grains demonstrated the highest recovery (70 %) in the рН = 5÷7 range compared to all the studied sulfides. Molybdenite and stibnite are floated at the level of 50 % under the same conditions. As pH increases towards the alkaline region, a decrease in the floatability of all sulfides except for chalcopyrite is observed. It was established that the highest recovery is achieved when the required time of conditioning with the collector is the inverse of their reactivity. The measured wetting angle of a drop of water on an untreated surface has the highest value (78°) for a gold plate, and the lowest one (67°) for pyrite, but the latter features the greatest increase in the wetting angle (by 15°) after treatment with butyl xanthate at a concentration of 10–4 mol/l and pH = 6. For molybdenite, treatment with butyl xanthate has practically no effect on the measured wetting angle. The Sb2S3 < PbS < CuFeS2 < FeAsS < FeS2 series is determined according to the electrode potential in the рН = 2.0÷5.6 range. Theoretical calculations and experimental data obtained when studying monofractions of sulfides and gold showed that experimental conditions (pH, conditioning time, collector concentration) significantly affect the floatability. The calculated reactivity of chemical sulfide compounds and gold in comparison with experimental results proved the importance of maintaining certain flotation conditions to create contrast in the floatability of minerals.
Effect of the structure and properties of welded zones made of Sv-AK5 welding wire at robotic surfacing
Authors: Nikitin K. V. , Dunaev D. A. , Zhatkin S. S. , Nikitin V. I.
Published: January 2023

The study covers the effect of welding arc current (47, 57, and 67 A) on the structure and properties of deposited samples obtained by robotic electric arc surfacing. Sv-AK5 (ER4043) welding wire of the Al-Si system was used as a filler material. Surfacing was carried out on a substrate in the form of a 6 mm thick plate made of AMg6 alloy (Al-Mg system). During surfacing, a typical two-phase structure of a hypoeutectic composition is formed in samples typical for Al–Si alloys with a silicon content of 5 %. Along the height of deposited layers, there is a tendency to structure enlargement in the direction from the substrate, which is associated with the accumulation of heat in layers deposited along the height. As welding arc current increases, α-Al-based dendrites and eutectic silicon crystals are refined with an increase in the density and a decrease in the microhardness of deposited samples. The increase in density is due to the reduced proportion and size of gas pores, as well as refined structural components. The decrease in microhardness is associated with the increased proportion of the soft phase (α-Al dendrites) and decreased quantity of hard eutectic silicon crystals. The average content of silicon in samples deposited in three modes is in the range of 5.46–5.91%, which corresponds to the chemical composition of Sv-AK5 (ER4043) welding wire. Higher welding arc current contributes to an increase in the tensile strength and a slight decrease in the offset yield strength and relative elongation. The features of changes in the mechanical properties of deposited samples are determined by of the specific cast structure of deposited layers formed under conditions of directional solidification in the direction from the substrate.
Finite element analysis of stress-strain state of the deformation zone of a UFG TI Grade 4 workpiece subjected to abrasive-free ultrasonic finishing
Authors: Asfandiyarov R. N. , Raab G. I. , Gunderov D. V. , Aksenov D. A. , Raab A. G.
Published: January 2023

An effective approach to increasing the fatigue resistance of metal products is to create compressive residual stresses on the surface of the product using surface plastic deformation (SPD) processing. One of the effective SPD methods is the process of abrasive-free ultrasonic finishing (AFUF). Another well-known approach to improving mechanical properties including fatigue resistance is to create an ultrafinegrained (UFG) structural state in the product. This research focuses on the finite-element study of the stress-strain state of a UFG workpiece subjected to SPD by the AFUF method. Commercially pure Grade 4 titanium in the UFG state obtained by the ECAP-Conform method was chosen as a workpiece material. In the course of the study, the stress-strain state of the deformation zone was analyzed after a single indentation with subsequent unloading under the elastic-plastic scenario. The effect of the indenter oscillation amplitude and its geometry on radial residual stresses including their depth of occurrence, average normal stress and strain intensity was analyzed. It was found that as the indenter radius increases, the strain intensity (e) value decreases. The e parameter distribution has a gradient nature with a decrease in values from the surface to the center of the workpiece. An analysis of simulation results shows that radial residual stresses in the deformation zone are predominantly compressive, and, accordingly, they will increase the fatigue resistance of the finished product. It was established that as the indenter oscillation amplitude increases, the values of compressive radial residual stresses also increase. Their maximum values reach 540 MPa at an amplitude of 75 μm with the depth of these stresses up to 0.3 mm. An increase in the indenter radius, i.e. in fact the contact area, leads to an increase in the magnitude of compressive radial residual stresses with an almost linear behavior.
Pyrometallurgical processing of deactivated nickel catalysts on Al2O3 carrier
Authors: Demidov A. I. , Kalmykov A. V. , Matveev I. A. , Shevchuk V. K.
Published: January 2023

The paper considers the use of deactivated nickel-containing catalysts based on Al2O3 as a significant raw material resource of one of the most important metals. The research highlights the features of this secondary nickel source that determine the acceptable methods of processing such raw materials. The effect of fluxing additives on the properties of the melt containing catalysts prepared beforehand has been studied subject to limitations as to their list (lime, fluorspar) in order to implement a pyrometallurgical method of metal extraction featuring by a relatively small amount of additives themselves. Due to induction heating used in combination with a graphite crucible, adding the total amount of fluorspar and marble additives close in mass made it possible to obtain the melt at a temperature slightly higher than the nickel melting temperature. In this case, the level of metal losses was about 2 %, which indicates the applicability of this method in laboratory conditions to ensure correct incoming analysis. It was proposed to use the pyrometallurgical method on an industrial scale using closed arc heating. To confirm this conclusion, experiments were conducted with a representative (more than 100 kg) amount of catalyst using a tailored arc furnace. Graphite chips were used as a reducing agent. The necessity of electrical matching of the load with the power source resulted in some adjustment of the fluxing additive ratio towards a reduction of calcium oxide content. As a result of a series of experiments, nickel with an up to 5 % iron admixture, similar in composition to the metal formed in the graphite crucible, was obtained. The presence of iron was caused by the fundamentally distinctive capability of the pyrometallurgical technology to reduce unstable compounds. Therefore it was suggested to use this metal for ferronickel production. The use of scarce fluorspar is justified by the fact that the resulting slag can be in demand in the production of fluxes for the electroslag remelting process.
Effect of heating VK and TK group hard alloys in various media on surface quality
Authors: Bogodukhov S. I. , Kozik E. S. , Svidenko E. V.
Published: January 2023

The studies carried out to explore the modifying effect on the surface of a hard alloy, surface alloying and thermochemical treatment of metal, thermal diffusion saturation, vacuum ion-plasma deposition demonstrated changes in surface roughness and performance. This paper used roughness to evaluate the behavior of various hard alloy groups when heated in various media. The samples were 5× 5× 35 mm bars and 15.8 ×15.8 mm tetrahedral plates made of VK8 and T14K8 hard alloys. Surface roughness parameters were measured on the profilometer implementing the contact (probe) method. Roughness values obtained were analyzed in the Microsoft Excel system based on an integral percentage and histograms were constructed. The effect of the heating medium on the surface roughness was studied both on bars and plates (with and without holes) using the saturating element/buffer substance (50–100 % BaCl2) melt. K4(Fe(CN)6 potassium ferrocyanide and Na2B4O7 borax were used as a saturating element (25 %). Microhardness and cutting wear were determined directly on the products (after determining the heating media effect on roughness). The heating of VK8 and T14K8 hard alloys in various media increases roughness and reduces cutting wear up to 2 times. The structure of initial materials before and after heating in various melts was studied using the JCM-6000 scanning electron microscope (Jeol Ltd., Japan) at a magnification of 1000–3000×. Plates in their initial state and after heating in various melts were subjected to resistance tests on the 1A616 screw-cutting lathe by face turning of an axle billet made of OS steel (similar in structure and properties to St45) 210 ×1650 mm in size of continuously cast metal (GOST 4728-2010). X-ray diffraction analysis of the VK8 hard alloy after heating in various media demonstrated the absence of changes in the phase composition. Along with this, there was a slight change in the carbide phase fine structure parameters of the alloy, namely a slight increase in micro-stresses with a simultaneous decrease in mosaic blocks.
Synthesis of cast materials based on MAX phases in Cr–Ti–Al–C system
Authors: Gorshkov V. A. , Khomenko N. Yu. , Kovalev D. Yu.
Published: January 2023

Two variants of the self-propagating high-temperature synthesis process, namely SHS from elements and SHS metallurgy, were combined to obtain cast materials based on the MAX phases of Cr2AlC and (Cr0,7Ti0,3)2AlC. Experiments involved mixtures with compositions calculated according to the chemical scheme 70%(Cr2O3 + 3Al + C)/(2Ti + Al + C) + + 30%(3CaO2 + 2Al). Synthesis was carried out in a 3 l reactor at an argon pressure of 5 MPa. The structure and phase composition of the reaction product were studied by X-ray diffraction and scanning electron microscopy. It was found during the research that the ratio of original reagents has a significant effect on the synthesis parameters and phase composition of desired products. The possibility of obtaining a cast material based on the titanium-doped Cr2AlC phase was shown. It was found that the resulting product is a composite material based on the (Cr1–хTiх)2AlC (х = 0,18÷0,28) phase, and the content of this phase is 43–62 wt.% depending on the original ratio of reagents. The material microstructure features by the presence of laminate layers with carbide grain inclusions. The end product contains carbide (Ti0,9Cr0,1C, Cr7C3, Cr3С2)and intermetallic (Al8Cr5, AlTi3)  impurities due to the insufficient life time of a melt formed in the combustion wave.
Production of high-entropy Fe–Cr–Co–Ni–Ti alloy by mechanical alloying and spark plasma sintering of a powder mixture
Authors: Kochetov N. A. , Rogachev A. S. , Kovalev D. Yu. , Shchukin A. S. , Vadchenko S. G.
Published: January 2023

A two-phase powder alloy based on substitutional solid solutions with BCC and FCC lattices was obtained by highintensity mechanical treatment (HMT) of a multicomponent Fe–Cr–Co–Ni–Ti powder mixture. Sample sections and particles of mixtures obtained were studied using an ultra high resolution field emission scanning electron microscope by scanning electron microscopy. XRD patterns of mixtures were recorded on the DRON 3 diffractometer with FeKα and CuKα radiation. It was found that after 10 minutes of HMT one intense superposition reflection remains on the XRD pattern with the angular position corresponding to Reflections 111 and 110 of phases with FCC and BCC lattices, respectively. A spark plasma sintering (SPS) method was used to obtain compact high-entropy material samples from the mixture after 90 minutes of HMT at 800 and 1000 °C. Their specific electrical resistance and density as well as the dependence of these properties on the sintering temperature were determined. It was demonstrated that the substitutional solid solution with the BCC lattice is probably enriched with titanium during the powder alloy SPS process.
Structure and properties of Ta–Si–N coatings obtained by pulsed magnetron sputtering
Authors: Sytchenko A. D. , Levashov E. A. , Kiryukhantsev-Korneev Ph. V.
Published: January 2023

Pulsed magnetron sputtering of a TaSi2 ceramic target 120 mm in diameter was used to deposit coatings on model silicon substrates at a gas flow rate ratio of Ar/N2 = 1/2 and frequencies of 5, 50, and 350 kHz. The structure and composition of coatings were investigated using scanning electron microscopy, energy dispersive analysis and glow discharge optical emission spectroscopy. The phase composition was determined by X-ray diffraction analysis using CuKα radiation. Mechanical properties were measured by the nanoindentation method using a Nano Hardness Tester equipped with a Berkovich indenter at a load of 4 mN. The heat resistance of coatings was evaluated by isothermal annealing in the air in a muffle furnace at 1200 °С, and oxidation resistance was estimated by the structure and thickness of the oxide layer. The results of structure studies have shown that the coatings are X-ray amorphous and have a dense homogeneous structure. Increasing the frequency from 5 to 350 kHz led to a decrease in the thickness and growth rate of the coatings. Samples deposited at 5 and 50 kHz showed high mechanical performance: hardness at the level of 23–24 GPa, elastic modulus of 211–214 GPa, and elastic recovery of 75–77 %. The coating obtained at the maximum frequency had a hardness of 15 GPa, elastic modulus of 138 GPa, and elastic recovery of 65 %. Annealing led to the formation of protective SiO2, Ta2O5, TaO2 oxide layers. A pronounced crystallization of the TaSi2 phase was observed, which is confirmed by the X-ray diffraction analysis data. Samples deposited at 5 and 50 kHz showed a small oxide layer thickness of 0.9 and 1.1 μm, which indicates the good heat resistance of coatings at 1200 °С.
Effect of mechanical activation and combustion parameters on titanium carbide SHS compaction
Authors: Bogatov Yu. V. , Shcherbakov V. A.
Published: January 2023

The paper presents the results of a study on the dense titanium carbide production by SHS compaction. It is shown that the use of a mechanically activated reaction mixture of titanium and carbon black powders makes it possible to obtain titanium carbide samples with a maximum relative density of 95 %. A feature of this research is that the mechanical activation of components and Ti + C mixture stirring were carried out in a ball mill. The study covers the influence of process parameters on the combustion properties and structure of the consolidated titanium carbide. It was found that the high-speed reaction mixture combustion is an essential condition for dense titanium carbide production. It was shown that the burning rate and temperature strongly depend on the size, mass and density of charge compacts. With an increase in the diameter (20–58 mm) and weight (10–70 g) of compacts made of mixtures with activated reagents, the burning rate varied from 10 to 100 cm/s, and the burning temperature varied from 2200 to 3100 °C. An influence of the pre-pressing pressure (applied at the combustion stage) on the burning rate and temperature was shown: the burning rate sharply decreases from 100 to 10 cm/s at pressures between 0 and 10 MPa, and the combustion temperature decreases monotonically from 3000 to 2000 °C at pressures between 0 and 40 MPa. A high-speed combustion mechanism was proposed for the titanium and carbon black reaction mixture where the formation of radial (longitudinal) cracks in compacts pressed from the mechanically activated mixture is an important factor. These cracks ensure the propagation of incandescent impurity gases and the exothermic reaction initiation in the sample volume.
Properties of WC–Co hardmetals as a function of their composition and microstructural parameters
Authors: Pesin V. A. , Osmakov A. S. , Boykov S. Yu.
Published: January 2023

Research into WC–Co submicron hardmetals involving measurement of hardness, coercivity and microstructural characterization, as well as analysis and comparison of results from recent literature led to the development of a unified constitutive expression for Vickers hardness in a form that separates the effects of the tungsten carbide grain size from those of the cobalt binder volume fraction. With the proposed expression for HV one may recalculate and compare hardness values for hardmetals featuring the same average grain size but differing in the binder matrix content. The paper shows that, in contrast to the Lee-Gurland model, the proposed constitutive expression framework treats the hardmetal hardness as a function of the carbide skeleton hardness (HWC) and contiguity (C) described as HV = CHWC. The carbide skeleton hardness depends on the WC grain size only, and it is described by the Hall-Petch equation. The results of parallel hardness and coercivity measurements led to an empirical equation relating Hc to the WC grain size and the Co volume fraction. Based on the complete experimental data, the relationship between the coercivity and Vickers hardness was explored, and a simplified relationship between these physical values was proposed to carry out the primary HV evaluation based on the measured coercivity values. As noted in the paper, the above equations are valid for relatively narrow WC grain size distributions with a maximum coefficient of variation of 0.5.
Refinement of the eutectic composition in the LaB6–VB2 system
Authors: Novoselov E. S. , Almjashev V. I. , Nesmelov D. D. , Danilovich D. P.
Published: January 2023

The LaB6–VB2 alloy with the eutectic structure was obtained by cold crucible induction melting followed by crystallization. The mole ratio of components in the initial powder mixture was 35 : 65. The structure and composition of the LaB6–VB2 material were studied by X-ray diffraction, scanning electron microscopy, and X-ray microanalysis. The composition of the alloy is represented by two boride phases — cubic LaB6 and hexagonal VB2. Two-phase eutectic regions up to 500 μm in size represent a LaB6 matrix filled with 0.8–2.0 μm thick VB2 fibers (filamentary, rod crystals). VB2 fibers are predominantly oriented along the direction of the temperature gradient that appeared when cooling the melt, i.e. from the outer surface of the sample to its center. The integrated phase area analysis was used to determine the eutectic composition: 42 Ѓ} 1 mol% LaB6 and 58 Ѓ} 1 mol% VB2.
Electrode processes in the production of microdispersed titanium powder by volumetric electrolytic reduction of its ions with sodium dissolved in the BaCl2–CaCl2–NaCl melt in the absence of titanium halides in the initial melt
Authors: Lebedev V. A. , Polyakov V. V.
Published: January 2023

The paper is devoted to a detailed study of cathodic processes, their influence on the anode process, and electrolysis performance. The polarization of a steel cathode in a CaCl2–BaCl2–NaCl melt at t = 610 °C was measured. The polarization curve clearly shows the potentials and current densities of the formation of a saturated sodium solution in the electrolyte (Esat = –2.97 V, ic = 0.04 A/cm2, lgic = –1,4), and the occurrence of sodium metal on the cathode (ENa = –3.22 V, iNa = 0.12 A/cm2, lgiNa = –0.92).

The value of Esat was used to calculate the concentration of sodium in the electrolyte at t = 610 °С (1.3·10–4 mol. fr.). The values of Esat, ENa, and their difference (E = 0,25 В) were confirmed by long-term electrolysis. These fundamental characteristics are the basis for process control and management. During long-ter 3 regions close to rectilinear ones were revealed: the discharge of sodium ions from supersaturated solutions at E more negative than Esat (from ENa to Esat), from mixtures of supersaturated and saturated solutions (at a constant E equal to Esat), from diluted solutions (with E more positive than Esat). The activity coefficients of sodium in supersaturated solutions are close to 1, which ensures their increased reducing ability. Maximum degrees of supersaturation (>100) are created at formation and decomposition on the cathode of metallic sodium nuclei, which are sufficient to intensify and prolong electrolysis, to lower the lower temperature limit of its realization from 600 to 350 °С. The formation of metallic titanium in the near-anode layer is explained by the disproportionation of Ti2+ ions entering the near-anode electrolyte from the anode surface and from the near-cathode melt.
SHS of highly dispersed powder compositions of nitrides with silicon carbide Review
Authors: Amosov A. P. , Titova Yu. V. , Belova G. S. , Maidan D. A. , Minekhanova A. F.
Published: January 2023

The application of the process of self-propagating high-temperature synthesis (SHS) to prepare highly dispersed powder nitride-carbide compositions from the most common refractory nitride (Si3N4, AlN, TiN) and carbide (SiC) compounds with a particle size of less than 1 μm is considered. The advantages of composite ceramics over single-phase ceramic materials and such trends of its development as the transition to nanostructured ceramics and the application of in situ processes of direct chemical synthesis of nanoparticles of components in the composite body are described. The attractiveness of the SHS process as one of the promising in situ processes characterized by simplicity and cost-effectiveness, the possibility of obtaining highly dispersed ceramic powders by burning mixtures of inexpensive reagents is shown. Considerable attention is paid to the consideration of the results of the application of azide SHS, based on the use of sodium azide and gasified halide salts as part of mixtures of initial powders of nitrided and carbidized elements during their combustion in nitrogen gas. The review of publications devoted to the application of SHS to obtain highly dispersed composite powders Si3N4–SiC, AlN–SiC and TiN–SiC, promising for use in sintering of the corresponding composite ceramic materials of submicron and nano-sized structure with improved properties, lower brittleness, good machinability, lower sintering temperatures compared with single-phase ceramic materials made of nitrides or carbides as well as for other applications, is presented. The results of the application of azide SHS are presented in detail both in the form of the results of thermodynamic calculations and the results of experimental research of combustion parameters, combustion product structure and composition. The advantages and disadvantages of using the combustion process for the synthesis of nitride compositions with silicon carbide, the causes of the disadvantages and the directions of further research to eliminate them are discussed.
Le culte du héros dans l’épopée négro-africaine, une pédagogie par la terreur à vocation éducative
Authors: KOUASSI Koffi Georges
Published: January 2023

Chaka, dans l’épopée négro-africaine, est un personnage actantiel au centre du culte. Dans ce culte, se profile une pédagogie qui, sous le voile de la terreur, éduque au refus de l’aliénation culturelle. En faisant de la tyrannie et la démagogie une arme de gouvernance, Chaka opprime son peuple tout en lui enseignant que la liberté s’acquiert par lutte dans la témérité et le courage au mépris de la vie individuelle. Aussi, le régime dictatorial qu’il a initié, s’il est répressif pour son peuple, est un moyen pour l’inciter au combat contre le colonisateur. Figure emblématique zulu, Chaka incarne la personnalité du rejet de la compromission de l’exploitation de l’homme par l’homme, engageant ainsi le peuple négro-africain sur la voie de la lutte pour l’indépendance politique, économique et culturelle.
Clinique de la déshumanisation du Tutsi rwandais dans la littérature fictionnelle numérique et imprimée sur le génocide
Authors: TIE Raoul
Published: January 2023

En interrogeant la clinique de la déshumanisation du Tutsi rwandais dans la littérature fictionnelle numérique et imprimée, notre ambition est d’insister sur le décloisonnement de l’objet culturel « littérature fictionnelle », ontologiquement agencée par le prisme du format papier, pour signifier ces nouvelles articulations par le truchement d’outils technologiques. Nous faisons donc dialoguer dans ce raisonnement deux interfaces de transmission du drame. Les récits fictionnels imprimés et numériques, médiations de l’événement qui fécondent une réception différenciée de la tragédie. Si le génocide performe des actes de cruauté, et souligne une rupture avec l’humanité, ce sujet articule en régime littéraire les mécanismes de ce déterminant passage de l’humain à l’inhumain. Décentrant le propos sur la négation du Tutsi rwandais du seul parti d’une herméneutique structurée par les historiens pour faire de la littérature ce nouveau lieu de passage et d’analyse de la mémoire historique et transculturelle sur l’événement.
Le visage humain à l'épreuve du vingtième siècle
Authors: VIRON Sébastien
Published: January 2023

Si le vingtième siècle fut celui des guerres mondiales, des camps d’extermination, de la bombe atomique et des anonymisantes explosions démographiques, il compte également à son morbide palmarès l’étiolement du visage, ce visage que les amoureux et les peintres ont pourtant chéri depuis le commencement du monde. Cet effacement de la figure humaine constitue sans doute l'aboutissement des événements historiques précédemment mentionnés. Du moins, c’est ce que l’œuvre littéraire de Romain Gary, aussi pertinente que prolifique, nous pousse à croire. Au cours de ses romans, l’auteur démontre que les dernières décennies, en révélant à l’homme ses innombrables tares, l’ont conduit à désacraliser son visage ou bien à le désensibiliser d’un monde jugé vicié, dont il ne faudrait plus faire partie sous peine de gravement se compromettre. Les régimes totalitaires et même les progressismes aux apparences les plus bienveillantes ont contribué à faire chuter cette idole millénaire, dont l’infini éthique et symbolique a été réduit comme peau de chagrin : des régimes concentrationnaires désireux d’abolir l’impératif levinassien aux sociétés modernes entretenant la chosification et la marchandisation des corps, la faillite est grande. L’individu ne peut alors que disparaître, au profit des objets ou des masses, pour qui la notion de visage relève de l’antithèse.
Le personnage des temps extrêmes chez Milan Kundera
Authors: YOMBO Jean Marie
Published: January 2023

La forme romanesque des temps extrêmes est, chez Milan Kundera, le lieu d’expression du tragique de l’homme contemporain surplombé par les déterminismes extérieurs, alors qu’il se grisait naguère de posséder le bâton de maréchal lui permettant de dominer la nature. Ainsi, avec Milan Kundera, le réalisme bourgeois ne constitue pas un axe pertinent pour l’analyse de cet « individu problématique » (Goldman 1964 : 23). C’est la raison pour laquelle, récusant la peinture des caractères, il montre, dans ses romans, que la vie intérieure du moi est devenue si insignifiante qu’on ne peut désormais le saisir qu’à partir des situations extérieures qui le surplombent. L’homme ainsi excédé se trouve face à une réalité qui lui échappe et se retourne contre lui. Cette situation montre que Kundera, dans le langage du roman, procède à ce que Foucault (1968 : 323) nomme « l’analytique de la finitude ». Le but de cet article est donc de montrer que les romans de Milan Kundera mettent en scène le tragique d l’homme trahi par le langage, déterminé par l’histoire et perverti par le règne de la technique, dans un monde par la technique.
La décrépitude de l’humain dans Temps de chien de Patrice Nganang et Verre cassé d’Alain Mabanckou
Authors: MFONZIÉ Zacharie-Blaise
Published: January 2023

Ce texte analyse la poétique de la décrépitude dans Temps de chien de Patrice Nganang et Verre Cassé d’Alain Mabanckou. En se référant à la sémiologie telle formulée distinctement par Yves Reuter et Philippe Hamon, l’article questionne les sous-entendus sur le choix des noms, des biographies et des statuts psychologiques et sociologiques des personnages opérés par les auteurs. Ces préférences esthétiques sont symptomatiques d’une écriture du désordre et d’un être contemporain déchu.
Substitution de l’humain dans Femme nue femme noire de Calixthe Beyala et Le dernier ami de Tahar Ben Jelloun
Authors: BIENGUI BEHALAL Bibiane Marina
Published: January 2023

Le présent travail s’articule autour des textes de Calixthe Beyala et Tahar Ben Jelloun, respectivement Femme nue femme noire et Le dernier ami. Il est question d’explorer dans ces œuvres, les mécanismes de substitution de l’humain, en faisant ressortir les différentes natures, fonctions de ce dernier, les procédés d’écriture et l’enjeu de ce style face à la place attribuée à l’être humain qui s’émeut et se sent libre en assouvissant ses désirs charnels. Les textes érotiques qui ont beaucoup plus centré l’attention sur la gent féminine nous permettront de voir à quoi est réduite la figure féminine aujourd’hui. Dans une utopie, les êtres de papiers se voient attribués des sexes des deux genres. La femme est perçue ici comme un objet sexuel, un fonds de commerce. Les enjeux d’une telle écriture relèvent du désir de calquer l’univers selon la perception du sort de l’humain.
Off-Shore de Philippe Braz
Authors: COULIBALY Amadou
Published: January 2023

La société capitaliste, dans son fonctionnement contradictoire, est devenue le centre d’intérêt d’une partie de la nouvelle génération de dramaturges français. Philippe Braz dont les pièces revendiquent une place de plus en plus importante dans le théâtre contemporain, s’illustre comme l’un des critiques d’une société qui s’auto-détruit à cause de l’argent. Off-shore, lue sous l’angle sociocritique défini par Duchet, s’offre comme une argumentation pamphlétaire et risible qui interroge sur la place de l’homme dans la société capitaliste en dévoilant la fin d’une richissime famille poursuivie par son passé et contrainte à l’exil. Le dramaturge instruit son public sur les limites de la puissance financière mal acquise qui ne peut nullement échapper à la justice divine même si elle parvient à se jouer de celle des hommes. Il dresse un sombre tableau de la cupidité qui pousse l’homme à briser le lien social entre lui et ses semblables.
Les modalités de la création du personnage-spectateur dans Play (2013) de Christoph Girardet et de Matthias Müller
Authors: KOVALOVA Svitlana
Published: January 2023

Passionnés des films hollywoodiens connus des années 50-60, les artistes allemands Christoph Girardet et Matthias Müller les ont examinés, en les réunissant avec quelques films allemands rares de la même période, pour trouver des scènes identiques, les découper et les réunir. Il s’agit des épisodes qui montrent des spectateurs de cinéma et leurs réactions : rire, applaudissements, agitation. Des images cinématographiques de quelques secondes, détachées du contexte des films de départ, forment ainsi un ensemble avec sa propre logique narrative – un court-métrage de 7 minutes intitulé Play (2003). Ces images multiples des émotions communes instantanées devant un spectacle, qui reste dans le hors-cadre, sont mises en concordance sonore et visuelle de telle manière qu’elles constituent une unité hybride des réactions émotionnelles en modulation. Le geste du montage change des rangs aux spectateurs. Pour le spectateur de l’oeuvre composée de cette manière, ces nouveaux personnages constituent un groupe qui agit selon la logique narrative de la vidéo ainsi obtenue, et celui qui la regarde est invité à suivre leurs réactions. Le travail des vidéastes déjoue l’idée du montage et de la réalité. Or, dans Play, le montage isole les épisodes des films fictionnels montrant les attitudes émotionnelles des spectateurs, pour les réunir ensuite. Il s’agit ainsi d’un montage réalisé d’après un autre montage, où le sujet est une réaction véridique initiale à la fiction initiale. Il serait intéressant de réfléchir à la spécificité des relations référentielles entre les corps et les images dans la création des émotions en considérant Play de Christoph Girardet et de Matthias Müller dans le contexte de la pensée de la figure de l’humain dans la littérature et le cinéma.
How leadership style matters for innovative work behavior
Authors: Gurbuz Gulruh , Gulec Burcu
Published: January 2023

Purpose- It is a clear fact that innovation and the ability to innovate is essential for organizations. Especially, actions of individuals are essential for continuous innovation and improvement. That’s why innovative behaviors of the individuals at a workplace have the utmost importance to achieve innovation regarding organizational level. Hence, to uncover the relationship between leadership styles and innovative work behaviors of the employees is the purpose of this study.
Methodology- In this study, the data has been collected through a questionnaire survey within the sample of white-collar employees of one of the special banks which operates in Turkey by using convenience sampling method. As a means of measurement, Leadership Style (MLQ) Scale by Bass and Avolio (2000) and Turkish Translation by Yurtkoru (2001) and Innovative Work Behavior Scale by de Jong and den Hartog (2010) and Turkish translation by Çimen and Yücel (2017) have been applied. Exploratory factor analysis, correlation and multiple regression analysis have been conducted. The main question to which this research tries to find answer is whether leadership styles have any significant effect on employees’ innovative work behavior or not.
Findings- Research results revealed that the leadership behaviors of the leader affect the employees’ innovation tendency or in other words, their innovative work behaviors.
Conclusion- Both transformational leadership and transactional leadership types have a significant effect on innovative work behavior of the employees. On the other hand, laissez-faire leadership type has no effect on innovative work behavior of the employees. In addition, this study provides conclusive evidence for further research that organizational culture, psychological factors and innovation climate in the organization can be put into the model as well to see the mediating or direct effect of leadership styles on employees’ innovative work behavior.
A Systematic Analysis on Graduate Theses Published in The Field of Computer Programming in K-12 Education Between 2018 and 2022
Authors: ULUYOL Çelebi , ORAK Esma , GÖKÇEARSLAN Şahin , RAMAZANOĞLU Mehmet
Published: January 2023

This study is designed to reveal the research trends of graduate theses published in the field of computer programming in K-12 between 2018 and 2022. Document analysis was used for data collection in this study. The data was divided into 9 categories, and the results demonstrated that the scholars in the Departments of Computer Educational and Instructional Technologies (CEIT) at Atatürk University and Ondokuz Mayıs University of Türkiye mainly published master’s theses in this field in 2019. Another result was that though CEIT is also the main department for doctoral theses, no difference exists in terms of years or universities. “Teaching, learning, and training programming” and "computational thinking" are the most frequently used keywords in graduate programs, respectively. While quantitative and mixed method (parallel, convergent), convenience sampling, and psychometric scales are preferred in master's theses, mixed method (explanatory, mixed), purposive sampling, interviews/focus group interviews, and psychometric scales are preferred in doctoral theses, respectively. Observation and semi-structured interview forms are used as data collection tools in the theses. Although quantitative methods are mainly utilized in data analysis, parametric and non-parametric statistical tests are also used, and content analysis is resorted to as part of qualitative methods. Whilst validity and reliability studies have been carried out measurement tools are employed in master's theses, scales have been developed in doctoral theses. The present study also offers some suggestions for future research on teaching computer programming
Common sense and quantum mechanics
Authors: SV Gantsevich
Published: January 2023

It is shown how changing only one word in the usual interpretation of quantum mechanics makes it possible to turn its puzzles and miracles into obvious trivialities
Enteric neuron activity in the mouse colon and responses to lumbosacral stimulation v2
Authors: Smith-Edwards Kristen
Published: January 2023

This protocol describes the steps for calcium imaging activity in the enteric nervous system (ENS) and interstitial cells of Cajal (ICC) in isolated colons and ex vivo lumbosacral spinal cord-colon preparations from GCaMP mice.
La capilla de Sabaletas
Authors: Arroyave Julio Cesar
Published: January 2023

El doctor Julio Cesar Arroyave es actualmente director de la Biblioteca Pública Piloto para el hemisferio occidental, en Medellín Colombia. Su disciplina primordial intelectual es la filosofía, materia en la cual ha sido profesor en la Universidad de Antioquia y autor de varias obras. Su sensibilidad cultural y gran capacidad de acción, le han llevado a la posicion distinguida que hoy ocupa como director de esta biblioteca de carácter continental. Fruto de sus inquietudes  en el campo de la historia, es el informe que hoy publicamos y que nos parece de gran importancia como una contribución a la etnohistoria y además como un estímulo para quienes se dedican a las investigaciones históricas, que en nuestra patria tienen motivos inagotables
A Quinoline-Based Fluorescent Labelling for Zinc Detection and DFT Calculations
Authors: Mohamad Nur Syamimi , Tan Ling Ling , Goh Choo Ta , Lee Yook Heng , Mobarak Nadhratun Naiim , Mat Lazim Azwan , Sapari Suhaila , Abdul Razak Fazira Ilyana , Hassan Nurul Izzaty
Published: January 2023

8-carboxamidoquinoline derivatives were gradually investigated as zinc's label in resolving weak water solubility, poor membrane permeability, and difficulty measuring free Zn2+ ion in cells quantitatively. The potential of 2-oxo-2-(quinolin-8-ylamino)acid (OQAA) as zinc's label was prepared and characterized spectroscopically. Theoretical and experimental data of OQAA were compared and discussed. The optimized molecular structure, molecular orbital of HOMO-LUMO, energy band gaps, and molecular electrostatic potential (MEP) of OQAA were carried out using the DFT method with Becke-3-Parameter-Lee-Yang-Parr (B3LYP) and 6-31G(d,p) basis set. The intermolecular interaction energy of OQAA-Zn is calculated by using the hybrid method of GEN with a basis set of LANL2DZ for Zn2+ ion and DFT/6-31G(d,p) for OQAA ligand. OQAA exhibited remarkable and excellent fluorescence enhancement selective and qualitatively only for Zn2+ than other metal cations tested (Fe2+, Cu2+, Co2+, Ni2+, Hg2+, Cd2+) under a long wavelength. Job's plot and 1H NMR titrations indicate OQAA-Zn2+ has a binding ratio at 1:1 stoichiometry (M1L1). Substantial shifting of amide N-H proton to higher chemical shift and intensity of the proton peak of N-H amide decrease abruptly implies that Zn2+ is binding to an amide. These changes confirmed interactions among the ligand OQAA and metal Zn2+ ion. As a result of the benefits discussed, OQAA could effectively and selectively optimize and fabricate for Zn2+ sensors.
Numerical Approach for Delay Volterra Integro-Differential Equation
Authors: Baharum Nur Auni , Abdul Majid Zanariah , Senu Norazak , Rosali Haliza
Published: January 2023

The delay integro-differential equation for the Volterra type has been solved by using the two-point multistep block (2PBM) method with constant step-size. The proposed block method of order three is formulated using Taylor expansion and will simultaneously approximate the numerical solution at two points. The 2PBM method is developed by combining the predictor and corrector formulae in the PECE mode. The predictor formulae are explicit, while the corrector formulae are implicit. The algorithm for the approximate solutions were constructed and analyzed using the 2PBM method with Newton-Cotes quadrature rules. This paper focused on constant and pantograph delay types, and the previous values are used to interpolate the delay solutions. Moreover, the studies also carried out on the stability analysis of the proposed method. Some numerical results are tested to validate the competency of the multistep block method with quadrature rule approach.
ANÁLISE DA CONCEPÇÃO DE EXAME ESCOLAR APLICADO EM MOÇAMBIQUE: CASO DA DISCIPLINA DE QUÍMICA DA 10ª CLASSE
Authors: Gomundanhe Almeida Meque , Teimoso Agostinho Rosário
Published: January 2023

O exame é uma das práticas avaliativas levadas a cabo nas escolas e constitui um dos principais instrumentos de avaliação que garantem a transição de classe dos alunos. Este estudo tem por objetivo analisar a concepção de exame escolar aplicado em Moçambique. Metodologicamente, optou-se pela pesquisa qualitativa. Para o processo de recolha de dados, foi usada a técnica de análise documental. Os documentos analisados foram o Regulamento Geral de Avaliação do Ensino Primário, Ensino Secundário Geral e Alfabetização e Educação de Adultos e a pauta de exame da disciplina de Química da 10ª classe, do Júri nº 4, 1ª época. A pauta analisada é referente ao exame realizado em 2019, numa das escolas secundárias que se localiza no distrito de Mandimba, Provínica de Niassa, em Moçambique. O tratamento e a discussão dos dados foram realizados por meio da técnica de análise de conteúdo. Os resultados evidenciaram que há uma maior valorização das notas obtidas no exame. Outros resultados demonstram que o maior número de alunos tem obtido notas baixas no exame, comparando com as de frequência. Isso tem ocasionado maior taxa de reprovação.
Palavras-chave: Avaliação. Exames. Notas.
Surgical treatment of vulvar cancer with perineal defect reconstruction using a VRAM flap. Clinical case
Authors: Korotkov V. A. , Petrov L. O. , Kasymov M. R. , Pasov V. V. , Skoropad V. Yu. , Tivkova L. V. , Yamshchikova A. S. , Grigoriev N. S. , Abramova O. E. , Naumov N. P. , Kaprin A. D. , Ivanov S. A.
Published: January 2023

The article presents a clinical case of perineal defect reconstruction using a VRAM flap in a patient with vulvar cancer. Stepwise surgical treatment method is described. A multidisciplinary meeting allows to realize a plan of surgical help for such patients with the goal of treating oncological process and its complications.

We have proposed a variant of perineal defect reconstruction through transfer of a vertical rectus abdominis musculocutaneous flap with a vascular pedicle.
Sperm DNA fragmentation in men vaccinated with Gam-COVID-Vac (Sputnik V)
Authors: Sorokina T. M. , Bragina E. E. , Sorokina E. A. , Sedova A. O. , Shtaut M. I. , Kurilo L. F. , Chernykh V. B.
Published: January 2023

Aim. To perform comparative analysis of sperm characteristics and DNA fragmentation in men vaccinated with GamCOVID-Vac (Sputnik V) and unvaccinated men.

Materials and methods. Characteristics ofsemen analysis and DNA fragmentation index in ejaculate samples of 122 men, 28 of whom were vaccinated with Gam-COVID-Vac (Sputnik V), were analyzed. Study participants did not have history of coronavirus infection COVID-19. Vaccinated patients were divided into 2 groups: group 1 (n = 10) included patients for whom the time between full vaccination (2 doses of the vaccine) and ejaculate sampling was shorter than 75 days; and the group 2 (n = 18) included patients for whom the time between vaccination and ejaculate sampling was longer than 75 days. Unvaccinated men comprised the control group (group 3, n = 94). Standard semen analysis was performed in accordance with the accepted laboratory guidelines of the World Health Organization (2010). DNA fragmentation was evaluated using fluorescent labelling of single- and double-strand DNA breaks (TUNEL).

Results. Totalsperm countin the group 1 was 265 ± 75 million, in the group 2 – 355 ± 67 million, in the group 3 – 304 ± 26 million. Progressive motile (PR)sperm in the group 1was 18.5 ± 1.9 %, in the group 2 – 23.2 ± 3.0 %, in the group 3 – 18.2 ± 1.1 %. Normal sperm morphology in the group 1 was 4.0 ± 0.5 %, in the group 2 – 5.8 ± 0.9 %, in the group 3 – 4.1 ± 0.3 %. The best ejaculate quality was observed in patients of the group 2, however, no statistically significant differences in semen analysis characteristics between the groups were found. Percentage of sperm with fragmented DNA (DNA fragmentation index, DFI) in the group 1 varied between 4.6 and 31.4 %, in the group 2 between 0.8 and 36.5 %, in the group 3 (control) between 1.3 and 39.8 %. Mean number of germ cells with DNA breaksin the group 1 (12.5 ± 2.4 %) was higher than in the group 2 (10.9 ± 2.0 %) and control group (10.5 ± 0.7 %), but with no statistical significance. Percentage of patients with DNA fragmentation index above the reference value (≤15 %) in the groups 1, 2 and 3 was 20, 22 and 18 % respectively. In 3 of 6 patients with increased DFI in the groups 1 and 2, this value was above the reference level even before vaccination.

Conclusion. No significant effect of vaccination with Sputnik V on sperm DNA fragmentation level in men was observed.
Steatocystoma multiplex of the scrotum. Clinical case
Authors: Scheplev P. A. , Rapoport L. M. , Korolev D. O. , Gorinova D. M. , Naumov N. P.
Published: January 2023

Steatocystoma multiplex is a disorder of the pilosebaceous unit characterized by multiple sebum-containing dermal cysts. We report the case of a 64-year-old male presented with multiple skin-colored, partially hyperemic cystic located in the scrotum area. They were accompanied by an active inflammatory process in the form of pain, swelling, hyperemia. The lesion was present for about 1 month. Previously, this patient had diagnosed with multiple steatocystoma located in the hip area and received surgical treatment.

At present, such reports in the scientific databases are presented sporadically, therefore we report on multiple steatocystoma of the scrotal localization due to its rarity.