bluuebunny/crossref_metadata_2025_split huggingface dataset:
Strength analysis of the conceptual model of a main rotor blade spar with actuators
Authors: Siadkowska K , Borowiec P 
Published: February 2021

Abstract
This paper concerns the conceptual design of a main rotor blade spar with actuators. A three-dimensional model of a main rotor blade is based on the preliminary geometric blade setting angle to increase the aerodynamic performance caused by different linear velocities of individual cross-sections. A modification of the blade setting angle results in a change of the angle of attack and influences the value of the lifting force in a given blade cross-section. The geometric setting angle was applied in designing both the main rotor blade spars and the blade. The overall dimensions of the blade depended on the available surface of the outmost blade airfoils. The important element of the designed spars was a cut in the form of a notch enabling the upper and lower crossbars of the designed spar to move during the operation of actuators. The FEM analysis was carried out on the parts of the designed blade spars. Three types of materials were compared in the finite element analysis. The internal stresses and displacements of the outmost edges of the crossbars were analyzed. The Catia V5 software was used for the designing work. The sections of the spars were analyzed using the Finite Element Method. The Pre/Post module of NX 12 was used for the FEM analysis. The displacement results were analyzed, which allowed us to determine their twist angle.
Application of chitosan for the removal of heavy metals from drilling fluids wastewaters
Authors: Wasag H , Kujawska J 
Published: February 2021

Abstract
The purpose of this study was to present a possibility of application of chitosan, covalently cross-linked by treating with glutaraldehyde as an effective sorbent of heavy metals ions from drilling wastewaters. The influence of the concentration and pH on the sorption capacity of the modified chitosan was determined in relation to Cr(II), Zn(II), Pb(II) and Cd(II) ions. Sorption parameters were defined. The greatest affinity to the modified chitosan was observed from ions of Zn(II), Pb(II). The effectiveness of the studied process is pH-depended. Processes of sorption of Cr(II), Zn(II), Pb(II) and Cd(II) ions in the presence of cross-linked with glutaraldehyde chitosan are well-described by Langmuir and Freundlich isotherms, which may be confirmed by high values of correlation coefficients (R>0.91). High values of the maximal sorption capacity (q0) have been reached for zinc ions (q0=3.67 mg/g) and lead ions (q0=3.31 mg/g), calculated on the basis of Langmuir isotherm equation which proves their great affinity to chitosan cross-linked with glutaraldehyde. Obtained results confirm good sorption properties of cross-linked chitosan towards heavy metals and a possibility of application of this sorbent in a wide range of the pH. Even small doses of sorbent, such as 5 g/L, facilitate the effective reduction of Cd, Cr, Pb, Zn content in drilling wastewaters, even from 75 to 90 %. Application of chitosan may be one of alternative and all the same effective methods leading to reduction of the inconvenience of fluid drilling waste.
Numerical analysis of porous materials subjected to oblique crushing force
Authors: Rogala M , Gajewski J 
Published: February 2021

Abstract
This article presents an analysis of porous materials subjected to oblique loading. The analysis was carried out with the Abaqus software using the finite element method. The material model used for numerical analysis was Crushable Foam. The subject of the study involved solid elements located on a base with a variable angle of inclination. The values of the base angle were 15, 30, 45, 60 degrees. All samples were loaded with the same boundary conditions. During the test, the normal and shear forces were determined. The crushing efficiency indicators were calculated from the measured forces. The aim of the tests was to define the distribution of forces in the foam element.
Effect of cut-out radius for behaviour of symmetrically laminated plates
Authors: Falkowicz K 
Published: February 2021

Abstract
The buckling and post-buckling behaviour analysis of thin-walled composite plate under an axial compressive force is hereby presented. The plate with central cut-out is made of a carbon-epoxy composite - a laminate consisting of eight symmetrically oriented plies. This paper addresses the influence of the cut-out radius on the buckling behaviour of laminated composite plates and stress concentration. To develop a discrete model and to perform numerical calculations the commercial ABAQUS program was used.
Dynamics of a nonlinear energy harvester with subharmonic responses
Authors: Litak G , Ambrożkiewicz B , Wolszczak P 
Published: February 2021

Abstract
A frequency transmission band of the nonlinear energy harvester shall be studied numerically. For the analysis, the nonlinear piezoelectric energy harvesting system based on a cantilever elastic beam has been applied to harvest the kinetic energy of the moving frame. We used a double-well potential induced by permanent magnets for a ferromagnetic beam resonator. A piezoelectric patch attached along the beam was used as a transducer of the mechanical into electrical energy. It occurred that the system could work in a wide interval of frequency beyond the linear resonance. Besides the response with a period of excitation, solutions with dominating sub-harmonics of the harmonic inertial force excitation have been found. Particular solutions were illustrated, classified, and discussed using phase portraits and Fourier spectra of the output signals.
Matrix profile implementation perspective in Industrial Internet of Things production maintenance application
Authors: Pizoń J , Kulisz M , Lipski J 
Published: February 2021

Abstract
The matrix profile processing is considered for the implementation of production maintenance tasks in the context of data acquisition by industrial Internet of Things solutions. The prospective implementation of the matrix profile data structure is verified through a dedicated case study, presenting the method of processing non-labelled data registered by sensors. The case study demonstrates the functionality of the profile and indicates the prospects of their applications in the field of production maintenance.
Alternative numerical solution of transient flow in viscoelastic pipes
Authors: Urbanowicz K , Bergant A , Duan HF , Karadzić U , Sobków D 
Published: February 2021

Abstract
A new numerical solution of transient flow simulations in viscoelastic pipes is presented, examined, and compared with traditional solutions and experimental results. Here the viscoelastic behaviour of the pipe wall is modelled explicitly and the wall shear stress implicitly. The new solution will be able to facilitate a better understanding of the unsteady flow behaviour in a plastic pipe in water supply systems. It will also contribute to lowering the computational costs of such systems and improving the accuracy of viscoelastic pipe diagnosis such as leak detection in the future.
Numerical investigation of the cavitating flow for constant water hammer number
Authors: Urbanowicz K , Bergant A , Karadžić U , Jing H , Kodura A 
Published: February 2021

AbstractSeveral comparative studies in this work were carried out with the help of the method of characteristics. This numerical method is the most effective for solving a system of partial equations (hyperbolic type) describing a complex problem associated with the water hammer phenomenon. The numerical tests have been performed for the selected constant value of the introduced dimensionless water hammer number. The presented comparisons showed that the unsteady flows without column separation are analogous in various hydraulic systems when the value of this number has been preserved. Besides, cavitating flows with such a constant value of this number were also tested. These studies indicated the existence of another dimensionless number which was called a cavitation number. Maintaining the fixed values of both dimensionless numbers guaranteed similarity of flows in different examined systems in which cavitation occurred.
Comparison of the use of species abundance and presence-absence data for diversity assessment
Authors: Kirichenko-Babko M B , Danko Y M , Danylkiv J M , Majerek D 
Published: February 2021

Abstract
The article is devoted to the analysis of empirical data on the distribution of ground beetles in three model sites located in Lublin (Poland). Using Principal Coordinates Analysis (PCoA) and hierarchical cluster analysis, we compared the results of the studies based on the data of species × abundance and binary data (species × presence / absence). It was shown that the hierarchical clustering method and PCoA based on binary data demonstrate the individuality of the studied territories, although they have some common species. While the results of the analysis, based on abundances, did not show a clear separation of the stations within the three studied locations, the similarity between the studied territories is more objectively reflected from a biological point of view.
Influence of diversified anthropogenic pressure on heavy metals contents in soils and plants of garden allotments
Authors: Żukowska G , Chomczyńska M , Myszura M 
Published: February 2021

Abstract
The presented research aimed at assessing the impact of anthropogenic pressure of varying intensity on the heavy metals content in the soils of garden allotments and in the biomass of plants grown there. In order to achieve the study purpose, the contents of Pb, Zn, Cu, Cd were determined in the soil samples of three allotments located in Silesia (strong industrial and urban pressure), Lublin (moderate industrial and urban pressure) and Biała Podlaska (weak urban pressure). The same elements were analysed in leaves and roots of red beets grown on the soils in urban areas mentioned above. It was found that the soils derived from Silesia were the most polluted, less polluted were the soils from Lublin, and the least polluted were the soils from Biała Podlaska. The content of Pb, Cu, and Cd in the leaves and roots of red beet harvested on the examined soils was dependent on the concentrations of these elements in soils. The obtained results indicated that the contamination of soils and plants with heavy metals should be included into the comprehensive assessment of the human impact on the environment, especially in industrial and urbanised areas, and suggested the need for further, widely spread studies of soils in such areas.
Strength analysis of the drive wheel hub of a hydrogen-powered prototype hyper-light vehicle
Authors: Gilewski M , Czarnigowski J , Górski W , Mitrus K , Różyło P , Trocha S , Wypychowski M 
Published: February 2021

Abstract
This article presents a strength analysis of the rear wheel hub of the prototype vehicle for the Shell Eco-Marathon competition. Due to only one wheel in the vehicle’s driving axle, all drive components and the wheel are subjected to higher loads. Therefore, the rear hub must withstand the loads generated by the rear part of the vehicle and the powertrain. The aim of the paper was to develop a hub with the minimum possible weight while fulfilling the strength conditions. The low weight of the hub is particularly important because of the efforts to achieve the highest possible efficiency of the drive system, which generates less energy loss and the ability to travel a longer distance on the same amount of fuel. The article presents the developed three-dimensional model of the hub. The suitable materials for the individual elements that are parts of the whole hub were selected. The three-dimensional model was tested to strength analysis using the finite element method with the use of Abaqus® software. The developed calculation mesh as well as the assumptions and boundary conditions of the modelling carried out are presented. The results of the simulation tests, which are the basis for further design work are also described.
Modification of carbon sorbents by ozonation
Authors: Mikhaylova E S , Fedorova N I , Ismagilov Z R 
Published: February 2021

Abstract
The paper presents the results of a study of changes in the textural and physicochemical properties of the carbon sorbent surface after oxidative modification with an ozone-oxygen mixture. For the study, we used a carbon sorbent sample obtained on the basis of long-flame coal. It is shown that oxidative modification with the mixture leads to an increase in the surface area of the studied sorbent, mainly due to the growth of micro-and mesopores. In this case, according to IR spectroscopy data, an increase in the content of oxygen-containing groups on its surface is observed.
Development of catalysts for the hydrogenation of levulinic acid to gamma-valerolactone in the framework of the problem of cellulose conversion into valuable chemicals
Authors: Okhlopkova L B , Ismagilov Z R 
Published: February 2021

Abstract
Gamma-valerolactone (GVL) is a starting reagent for the production of fuels and fine chemicals. GVL can be used as a solvent, as part of an electrolyte, for the production of chemicals and fuel additives. It can be converted to liquid fuels such as valerian biofuels, liquid alkanes or valuable chemical intermediates such as 1,4-pentanediol or alkylpentenoates being biopolymer precursors. The production of GVL is based mainly on the hydrogenation of levulinic acid (LA), which can be obtained directly from cellulose by acid hydrolysis. This article describes the development of heterogeneous catalysts for the targeted conversion of LA to GVL. In order to analyze both achievements and unresolved problems in this area the emphasis was placed on the discussion of systems based on noble and non-noble metal catalysts, hydrogenation by means of hydrogen transfer.
Transmission electron microscopy for evaluating the structural parameters of nanoparticles
Authors: Zakharov N S , Popova A N , Zakharov Yu A , Pugachev V M , Russakov D M 
Published: February 2021

Abstract
In this work, on the example of bimetallic systems FePt and FePd, an approach is developed to assessing the structural parameters of nanoscale mono-and polymetallic systems by transmission electron microscopy (TEM), in comparison with the X-ray diffraction method of analysis. The interplanar distances, average sizes and phase compositions of FePt and FePd nanosystems are calculated.
Synthesis of nanostructured FePt systems
Authors: Zakharov N S , Popova A N , Zakharov Yu A , Pugachev V M 
Published: February 2021

Abstract
The paper compares some characteristics of nanoparticles of the FePt system obtained by the method of joint reduction of solutions of metal precursors using different reducing agents: an alkaline solution of hydrazine hydrate and sodium tetrahydroborate. The method of transmission electron microscopy is used to analyze the shape and morphology of the obtained nanosized particles, according to the data obtained by the methods of X-ray diffraction, phase analysis is carried out and the main X-ray structural parameters are evaluated. Thermal analysis in combination with mass spectrometry is used to characterize the state and purity of the surface of nanoparticles. It is shown in the work that nanoscale FePt systems obtained using the reductants selected in the work have similar physicochemical characteristics.
Study of coke by X-ray structural analysis and scanning electron microscopy
Authors: Ismagilov Z R , Popova A N , Sozinov S A 
Published: February 2021

Abstract
In this work, a number of industrial samples of needle cokes from various manufacturers were studied. The study of the samples was carried out by methods of X-ray diffractometry and analytical scanning electron microscopy. The parameters of their crystal structure were determined, and the features of their microstructure were investigated. The differences found in the crystal structure and morphology of coke particles made it possible to divide the studied samples into 2 groups: isotropic, with equal longitudinal and transverse crystallite sizes, and anisotropic, in which the longitudinal crystallite sizes exceed the transverse ones by 3-4 times. Particles of isotropic cokes have a fracture texture characteristic of a glassy amorphous body, in contrast to which particles of anisotropic cokes have a lamellar texture. The consistency of the conclusions obtained from the results of two independent methods makes it possible to consider X-ray diffraction analysis in combination with analytical electron microscopy as the necessary complementary tools for evaluating cokes with the aim of their possible application in various technological processes.
Glow of a coal flame during exposure to microsecond laser pulses with different energy densities
Authors: Kraft Ya.V. , Aduev B. P. , Nurmukhametov D.R. , Ismagilov Z. R. 
Published: February 2021

Abstract
The kinetic characteristics of the glow of coal during exposure to microsecond laser pulses have been investigated. It is shown that the glow intensity increases from the moment of exposure to the laser pulse, the maximum glow intensity falls on ∼ 110-120 µs• i.e. at the end of the laser pulse. In the submillisecond range, a decrease in the glow intensity is observed. The glow intensity of coals increases linearly with an increase in the energy density of the laser radiation.
Study Of Fossil Coals In The Kuznetsk Basin By Epr Spectroscopy
Authors: Nelyubina N V , Nikitin A P , Valnyukova A S , Ismagilov Z R 
Published: February 2021

Abstract
Fossil coals of the Kuznetsk Basin of varying degrees of metamorphism were studied by the method of electron paramagnetic resonance. It is shown that in the series from brown coal to anthracite, the g-factor of the EPR signal decreases, due to the aromatization of the carbon framework and a decrease in oxygen-containing and hydrogen-containing fragments in the coals. The maximum width of the EPR spectrum is observed for coals of the middle stage of metamorphism, which indicates the presence of both aliphatic and aromatic paramagnetic centers (PCs) in their structure. Also, in the series of coal metamorphism, the concentration of PCs increases. Thus, it has been shown that in the process of coal metamorphism, a change in the electronic structure occurs, associated with the rearrangement of the carbon skeleton of the organic mass of coal (OMC) and a decrease in the amount of oxygen-containing and hydrogen-containing radicals.
Adsorption method for determining the texture characteristics of Kuzbass fossil coals of the metamorphism series
Authors: Dudnikova Y N , Zykov I Yu , Fedorova N I , Ismagilov Z R 
Published: February 2021

Abstract
The presented work is devoted to the study and development of a technique for measuring the parameters of the porous structure of fossil coals in Kuzbass by the adsorption method on an ASAP 2020 analyzer “Micromeritics”. The conditions for sample preparation of samples were selected, which make it possible to record reproducible isotherms of low-temperature adsorption-desorption of nitrogen (77K) by the studied samples of fossil coal of various grades. The obtained isotherms of low-temperature adsorption-desorption of nitrogen were used to determine the textural characteristics of Kuzbass fossil coals by various methods (the specific pore surface area was calculated using the Brunauer-Emmett-Taylor (BET) method; the volume of micropores was determined using the comparative t-Plot method; the mesopore volume was determined using the method of Barrett-Joiner-Halenda (BJH). The obtained values of the textural characteristics of Kuzbass coals of the metamorphism series make it possible to reveal their macro-and microstructural features, to obtain information on the adsorption properties of coal, and can also be used to optimize coal use processes, such as the extraction of methane from coal seams, gasification, combustion, liquefaction, beneficiation, production of metallurgical coke.
Study of the textural characteristics of carbon sorbents prepared by alkaline activation
Authors: Zykov I Yu , Dudnikova Y N , Tsvetkov V E , Fedorova N I , Ismagilov Z R 
Published: February 2021

Abstract
The paper investigates the textural characteristics of carbon sorbents prepared by alkaline activation of brown coal from the Tisul deposit. The texture characteristics (specific surface area-SBET, m2/g, total pore volume-VΣ, cm3/g, mesopore volume-Vme, cm3/g and volume of micropores-Vmi, cm3/g) of carbon sorbents were measured on an ASAP-2020 analyzer. The production of carbon sorbents was carried out by activating coal impregnated with potassium hydroxide at a KOH/coal (RKOH) ratio of 0.5 g/g; 1 g/g and 2 g/g. The activation of brown coal was carried out at three different temperatures-700 °C, 750 °C and 800 °C. It is shown that the RKOH ratio has a greater effect on the texture characteristics of carbon sorbents, as compared to the effect of the alkaline activation temperature. Alkaline activation at an RKOH ratio of 2 g/g makes it possible to obtain carbon sorbents with the highest values of textural characteristics. High-temperature alkaline activation (800 °C) has a positive effect on the formation of a common pore space of carbon sorbents based on brown coal from the Tisulsky deposit for all studied RKOH.
Methods and approaches to the determination of the carbon-containing dust concentrations in the atmospheric air during coal mining and processing
Authors: Zhuravleva N.V. , Zhuravleva E.V. , Mikhailova E.S. , Ismagilov Z.R. 
Published: February 2021

Abstract
An overview of russian and foreign methods and approaches to control carbon-containing dust in the atmospheric air in the influence zone of coal mining and processing enterprises is presented in this paper. The main composition of suspended substances (coal dust), entering in the atmosphere in the processes of coal mining and processing, consists of an inorganic part, represented by the main rock-forming oxides, toxic elements, mineral particles PM2,5 and PM10, also organic substances, which include soot(carbon), organic matter of coal, benz(a)pyrene and other PAHs. The capabilities of modern physical and chemical analysis methods, which significantly increase the accuracy, reliability and information content of monitoring the state of atmospheric air, are still poorly used in industrial environmental control. Information about the composition and properties of coal dust obtained from research of Kuzbass coals, its mining and processing waste should be used in the development of industrial environmental monitoring programs by industry enterprises.
The development of ecologically clean technology for coal use in terms of the coal-water slurry usage
Authors: Korotkiy I A , Neverov E N , Murko V I , Chernikova O P 
Published: February 2021

Abstract
The baseline conditions of technology for producing and burning coal-water slurries in Russia and foreign countries is exposed. The technological and economic efficiency of using this technology for the coal processing and cleaning waste disposal is shown at experimental and industrial facilities. The feasibility studies of the technology usage at large Kuzbass thermal power plants are presented. The possibility of solving a serious environmental problem of reducing the storage of the most coal washing toxic waste volume in the areas where coal processing plants and coal mining enterprises are located is demonstrated. It is shown that on the basis of these wastes, it is possible to prepare a suspension coal-water fuel with a solid phase content of 56-59%, with the required structural and rheological characteristics and a lower calorific value of up to 13 MJ/kg. The boiler with a thermal capacity of 0.58 MW with an eddy combustion system, which effectively operates on coal-processing waste fuel is designed, manufactured and tested. The results of the boiler operation on the specified fuel showed its high efficiency (efficiency is 83-85%) with the level of harmful emissions in the flue gases significantly lower than the permissible values.