bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of the beneficial utilisation of urban sewage sludge using modern analysis methods
Authors: Smirnov Yu D , Suchkova M V
Published: November 2019

The article presents Russian and foreign experience in the recycling of sludge of urban sewage wastewater with the prospect of the beneficial use of both the direct waste and the products of its processing. Special attention is also paid to the problem of recycling of ashes of sewage sludge incineration. The article also considers the possibility of applying modern methods of analysis (such as X-ray fluorescence analysis, spectroscopy, biotesting) to develop a composition of the ash-based soil mixture. The study is realized on the laboratory and experimental base of the accredited Center for the collective use of high-tech equipment of Saint-Petersburg Mining University (as a part of state task for 2018-2019 year).
Metrological support management quality assessment
Authors: Smirnova E E , Strizhova T A
Published: November 2019

The article presents data on assessing metrological support management quality based on the probabilistic approach. Assessing event probability can be additional important information in planning and analyzing complex processes such as metrological management. The analysis was carried out by comparing the requirements for metrological support with information about real situations. Requirements for metrological support are developed on the basis of regulatory legal acts, company management instructions, optimization of resource consumption, as well as taking into account company development prospects. To a large extent, the achievement of metrological support goals depends on management quality. The final step in assessing the quality of metrological support management is development of the results of assessment and formulation of conclusions (recommendations).
Improvement of the system of industrial environmental monitoring of atmospheric air in the area of anthropogenic arrays impact
Authors: Strizhenok A V , Korelskiy D S
Published: November 2019

Nowadays the waste management is one of the most pressing problems in the industry of mineral resources extraction and processing. The main method of waste disposal is storage on the surface of the Earth in the form of anthropogenic arrays. Anthropogenic arrays have an integrated and long-term impact on the atmospheric air. In this regard, the need for continuous monitoring of the state of atmospheric air in order to identify the main sources of dust emission and their quick elimination acquires particular relevance. This task can be performed by automating the existing system of industrial environmental monitoring. The article touches upon the issues of the implementation of the task of continuous monitoring of the dust content of atmospheric air in the areas of the anthropogenic arrays impact. The structure of the automated system of industrial environmental monitoring for the rapid detection of sources of intense dust emission, their ranking by the degree of potential danger and the measures for their timely elimination are proposed.
Ecological and economic justification of the utilization of associated petroleum gas at small oil fields of Russia
Authors: Strizhenok A V , Korelskiy D S
Published: November 2019

One of the main environmental problems in oil production in the world today is the utilization of associated petroleum gas (APG) by combustion it in flares. At the same time, this process has enormous economic damage, since APG is a potential raw material that can be used to produce marketable products, power or heat energy. More than 30 billion cubic meters of APG are combusted in flares annually only in Russia, which is about 20% of the total amount of combusted APG in the world. It should be noted that combustion of 1 billion cubic meters of APG is equivalent to the loss of marketable products worth more than 300 million dollars. In the present article, the authors carried out a selection of the optimal method for utilization of APG at small fields in Russia and its environmental and economic justification. The method of power generation directly at the field using gas turbine power station was adopted as the most cost-effective method. The implementation of such a project at the field reduces emissions of pollutants hundreds of times, and payback period does not exceed 2.5 years.
Accounting for the effects of third elements in the emission spectral analysis and construction of global analytical techniques
Authors: Sukhomlinov V S , Mustafaev A S , Popova A N , Koubaji H
Published: November 2019

The paper discusses the method of processing the metals and alloys spectra, which were obtained using emission spectrometers with spark excitation spectra. The proposed technique makes it possible to build a global method for analyzing any alloys, taking into account the so-called “third elements effects”.
Instrumental virtual tools for measuring random signal characteristics
Authors: Sytko I I , Smirnova E E
Published: November 2019

Based on modern computer technologies developed by National Instruments, a virtual device for adjusting, controlling and studying various noise characteristics has been developed. Signs helping identify the laws of random signal probability distribution are smoothness or sharpen-ing, asymmetry and uncertainty. Examples of identification of noise characteristics of elec-tronic devices are provided; instrument technologies are used to monitor the technical condi-tion of such devices.
Development of a local quasigeoid model for Vietnam land area using the global EGM2008 model
Authors: Son Tran Thanh , Kuzin A A , Mustafin M G
Published: November 2019

The article presents the results of research on the development of methods for obtaining normal heights in Vietnam using the global geoid model EGM2008 and software for processing GNSS measurements. The errors between the normal heights computed by the global model of the EGM2008 geoid and the heights found by GNSS measurements and geometric levelling on the territory of Vietnam are determined. The localisation method for the global geoid model EGM2008 for Vietnam’s territory is suggested, such a geoid model is practically formed as the EGM2008_ TN file. Tests of the developed technique and the localised model of the EGM2008__TN geoid were carried out, showing the possibility of its application to obtain normal heights from GNSS measurements in Vietnam with the 4th levelling accuracy class.
Validation of the method of height transmission by laser tape measure in construction
Authors: Son Tran Thanh , Kuzin A A , Mustafin M G
Published: November 2019

The article deals with the features of the use of laser tape measure for the transfer of heights from the Earth surface to the upper levels in civil engineering and to a mine in surveying. The most suitable engineering solution for the transfer of height to the mine is justified. Certain experimental results are presented. The algorithm that increases the accuracy of the transmission marks to the mine in the construction of deep tunnels is developed.
Automation of laboratory studies in the determination of the mass of mechanical impurities in petroleum
Authors: Serzhantova M P , Tynchenko V S , Bukhtoyarov V V , Bashmur K A , Tynchenko V V , Kukartsev V V
Published: November 2019

The article solves the problem of automated control of laboratory research process in determining the mass of mechanical impurities in petroleum. The research analyzed the features of the test and identified the need for an automated control system of this test. The developed automated system controls the filtering process of the sample and pump power, allows simultaneous parallel studies on independent suction lines, while optimizing the pump motor power, depending on the number of used lines. The article provides a block diagram describing the basic system algorithm and scheme of the laboratory tests automated installation in determining the mass of mechanical impurities in petroleum. The result is a reduction in the complexity of the study, optimization of laboratory research.
Similarity criteria for modeling the process of pipes pulse pressing into the tube sheet
Authors: Tynchenko V S , Petrovsky E A , Bukhtoyarov V V , Bashmur K A , Tynchenko V V , Kukartsev V V
Published: November 2019

In the presented article, the phenomena that characterize the essence of the process of fastening pipes to the tube sheet by the method of electropulse pressing are described. The article presents the results relating to methods and means of measurement, testing and operation of products in engineering, including theoretical studies of methods for fastening heat-exchange tubes into a tube sheet. The disadvantages of traditional methods of fastening pipes to the tube sheet are revealed. The analysis of the prospects of pipes electropulse pressing into the tube sheet is conducted. Using the dimensional analysis method, similarity criteria were obtained for the process of electropulse press-fitting of pipes into a tube sheet, which allow extending the results obtained on a reduced-scale model to products of natural dimensions.
Simple universal Kelvin equation valid in critical point vicinity, external-internal state correction, and their application in understanding of normal pentane capillary evaporation and condensation in mesoporous silica MCM-41
Authors: Valeev A A , Morozova E V
Published: November 2019

A new simple universal form of the Kelvin equation, which can be used near the gas-liquid phase transition critical point, and the correction of the pressure and density for gas phase fluid outside the porous medium are used for the normal pentane meniscus effective curvature radius calculation at the phase equilibrium in mesoporous silica MCM-41, on the basis of the capillary evaporation and condensation experimental data. Normal pentane is suggested as a promising fluid for characterizing the porosity that can be used even at room temperature.
Implementation of fuzzy logic in the smelting process of control algorithms of copper-nickel sulfide materials
Authors: Vasilyeva N V , Ivanov P V
Published: November 2019

The analysis of control quality of technological process of melting of copper-Nickel sulfide materials is carried out. The structure of the automatic melting control system is proposed, information and control channels are described. The algorithm of process control using fuzzy logic, which allows stabilizing the copper content in the matte within the specified limits.
Non-contact methods and means of measuring the oil film thickness on the water surface
Authors: Ushakov I E , Vinogradova A A
Published: November 2019

The article discusses options for solving the problem of ocean pollution by oil products. Currently, it is important to measure the thickness of an oil film to obtain information on the volume of spills and operations to eliminate them. The features of non-contact methods and the main characteristics and conditions of the use of means for measuring the thickness of an oil film are discussed. The accuracy of measurements in real conditions (in the presence of surface waves) was identified.
Noise immunity of signal demodulation procedure in binary coded communication channels with a frequency-position multiplexing
Authors: Vyboldin Yu K , Borisov S V
Published: November 2019

The article presents the algorithms for demodulating binary channels of data transmission lines with frequency multiplexing used in remote control and warning systems. The noise immunity of the algorithms were investigated. It is shown that significant simplification and significant noise immunity increasing can be obtained by applying the majority decision rule.
Nuclear magnetic resonance methods – the key to determining the structure of organic substances
Authors: Kuzhaeva A , Zgonnik P V , Anisimova N A
Published: November 2019

This article is intended to help an organic chemists and industrial engineers to choose a suitable method for the analysis of substances with complex structure and its control in industry. In the paper the current level of the NMR development and analytical abilities of the different NMR techniques is considered. It is noticed, that as a rule the results of the one-dimensional NMR are quite difficult to interpret in the case of a complex molecular structure. The main principles and different varieties of two-dimensional NMR techniques are described.
Presentation of distortion power in an alternating current network and analysis of factors of its occurrence
Authors: Myatezh S V , Novolodskiy M V , Kitova E T , Konyukhov V Y , Daudov I M
Published: November 2019

The article examines the conditions for the appearance of such components of inactive power in electric alternating current networks, which are known as reactive power and distortion power. Through simulation modeling, the validity of the expressions that were obtained analytically and determine the components of inactive power was verified. The validation of expressions based on theoretical concepts. The results are useful in optimizing modes in AC networks and creating effective technical means of compensating latent capacities.
Generalization of solubility of aromatic substances in supercritical fluid media with the use of entropy method of similarity theory
Authors: Bilalov T R , Gumerov F M , Neindre B Le
Published: November 2019

The results of generalization of the solubility of aromatic hydrocarbons in supercritical carbon dioxide using the entropy method of similarity theory are presented. The subject of generalization was the experimental data of various authors on the solubility of 11 substances studied in the temperature range from 300 to 350 K (total 823 experimental points and 57 isotherms).
Comparative study of scaling models related to thermodynamic properties of H2O in the critical region
Authors: Ustyuzhanin E E , Ochkov V F , Rykov S V , Rykov V A , Znamensky B E , Ya Tun Aung Thu
Published: November 2019

An analysis of some literary sources is made in the report. They contain data on thermodynamic properties (the liquid density (ρl
), the gas density (ρg
), the mean diameter, (fd
), the pressure (P) on the saturation line) of H2O. We have considered also scaling models, ρg
(τ, D, C), ρl
(τ, D, C) (Anisimov et al, 1990), here τ is the relative temperature, D = (α, β, Tc
…) are critical characteristics, (α, β) are critical indices, C are adjustable coefficients. A scaling model, P(τ, D, C), (Abdulagatov, 2007) is taken in account. These models meet the scaling theory of critical phenomena (ST) and work in the interval, τ = (0.002 – 0.012). We have paid attention to a model, fd
(τ, D, C), (Anisimov et al, 1990). It describes fd
, includes the leading component with (1 – α) index and is adapted to H2O. Another type of fd
(τ, D, C) is developed in this work. Our model is different from fd
(τ, D, C) (Anisimov et al, 1990). Its structure is combined and contains the leading component with 2β index. Similar combined scaling models have been developed too for properties (the order parameter, fs
, ρl
, ρg
, P). There are got numerical estimates of parameters those are related to functions (fd
(τ, D, C), ρg
,(τ, D, C), P(τ, D, C)) et al.) and based on (ρl
, ρg
, P, T) data, which are placed in the interval 3 × 10−3 < τ < 0.33 and related to the formulation IAPWS–IF 97 of H2O. The set of equations let us determine (ρl
, ρg
, P, T) values in the interval 10−5 < τ < 10−2 including the extrapolation region. A comparative study is performed: we have compared our numerical values with (ρl
, ρl
, P, T) data those are determined on the basis of the equation of state (the formulation IAPWS–IF 95). The difference between two data sets is analyzed.
An experimental study of the density of the helium – neon – nitrogen gas system at low temperatures
Authors: Milyutin V A
Published: November 2019

An experimental installation has been created at the Department of TOT to measure the density of ternary gas mixtures from 100 to 300 K and pressures up to 16 MPa. The experimental density for the He–Ne–N2 system is determined by the constant volume piezometer method. The amount of substance in the piezometer is measured by the volumetric method. He–Ne–N2 mixtures are prepared in a special mixer at 20°C for the p-v-T series of experiments, the concentrations are calculated using the equations of state of pure components. In the experiment, 3 mixtures were prepared, which had mole concentrations: (xHe = 0.24; xN2
= 0.17), (xHe = 0.33; xN2
= 0.34), (xHe = 0.16; xN2
= 0.60). 70 experimental points on 7 isotherms were obtained.
The method for constructing the fundamental equation of state for SF6
Authors: Kudryavtseva I V , Rykov V A , Rykov S V
Published: November 2019

The paper investigates issues related to construction of the equation of state which takes into account the peculiarities of substance behavior in the critical region and which is associated with the scalihg theory of critical phenomena. Construction method of a unified fundamental equation of state (UFEoS) for SFß that satisfies the power laws of scaling theory (ST) and the requirements imposed on the fundamental equations of state of the virial form (FEoS) is considered. UFEoS is based on a new representation of the scaling hypothesis in variables density – temperature and Benedek hypothesis. The authors have developed FEoS for SF6 in the range of state parameters: in density up to 2000 kg/m3, in temperature from 223.555 to 650 K. The authors have performed comparison with the certain fundamental equations of state for SF6: Scalabrin et al (2007 J. Phys. Chem. Ref. Data 36 617), Guder et al (2009 J. Phys. Chem. Ref. Data 38 33); Bezverkhii (2017 High Temp. 55 702). It is shown that in accordance with the requirements of ST, in contrast to the certain FEoS, the proposed equation of state transmits SF6 behavior into the vicinity of the critical point and in this region of state parameters significantly exceeds them in accuracy.
Thermophysical properties of high energy synthetic hydrocarbons
Authors: Yanovskiy L S , Varlamova N I , Kazakov A I , Molokanov A A , Plishkin N A
Published: November 2019

The vapor pressure, enthalpy and entropy of evaporation, boiling point and critical parameters of four synthetic frame and spiranic hydrocarbons of interest for use as aircraft synthetic fuels or their components have been investigated
Equations for calculation of liquid-vapor equilibrium in binary mixtures containing methane
Authors: Vasserman A A , Galkin V N
Published: November 2019

Equations describing the experimental data on liquid-vapor equilibrium in binary mixtures of methane with argon, carbon dioxide and helium have been compiled. The equations describe the dependence of pressure of liquid or vapor on temperature and composition. When compiling them, the program selected most significant coefficients of the equations. The standard deviations of experimental values of pressure from the calculated values range from 1.8 to 5.0%. The equations make it possible to determine the composition or temperature of the phases at known values of other parameters of phase equilibrium.
Fundamental equation of state for R1234yf
Authors: Rykov V A , Rykov S V , Sverdlov A V
Published: November 2019

Unified fundamental equation of state for R1234yf has been developed that satisfies the scaling critical point theory. It has been demonstrated that the proposed equation of state truly represents the peculiarities of the thermodynamic surface from the qualitative and quantitative point of view: first, in the regular part of the thermodynamic surface, secondly, in the region of strongly developed density fluctuations. The operating range of the equation of state has been determined on the basis of the benchmarking analysis with experimental and estimated data: for temperature 230 ≤ T ≤ 420 K; for pressure 0.001 < p < 20 MPa.
On round dates, acute issues and solving problems of low-parametric equations of state by logical abduction
Authors: Petrik G G
Published: November 2019

Within the framework of a simple molecular thermodynamic model, the problems of comparing equations of state (EOS) and the choice of analogs in three sets are analyzed: equations based on the model of interacting point centers, van der Waals type equations, and Martin equations derived from volume translation. A method for the selection of EOS was proposed and approved by calculating the critical isotherms Ar and C4F8. According to the results of the PV calculations, the selected EOSs turned out to be better than known those of Peng-Robinson, Martin, Redlich-Kwong. On the basis of a new characteristic of the equation, a parameter comparing the configuration contributions, a method has been proposed for choosing EOS-analogs in different families. An explanation is given for the impossibility of describing equally well with one equation two states with a reduced density of 2 and 3/2. The results obtained for the EOS of the new model confirm its adequacy in full accordance with the method of abduction.
Calculation of thermophysical properties of binary helium-based gas mixtures
Authors: Kochurov D S , Eletskiy I A , Kotova E S
Published: November 2019

A modified methodology for calculating thermophysical properties of binary helium He based mixtures with a heavier gas component is presented. To obtain the properties of the pure components and mixtures in the limit of zero density, the most recent ab initio calculation results and modified mixing rules are implemented. To calculate the properties at high pressures, the extended laws of corresponding states are used. A verification procedure was carried out, and the results are presented for deviations of calculated thermal conductivity λ and dynamic viscosity μ values from available experimental data for mixtures He-Ar and He-N2 at temperatures from 183 K up to 603 K, and pressures up to 10 MPa. It is shown that in the considered range of thermodynamic parameters the deviations of the calculation results from the experimental values are less than 3 % for λ and less than 2 % for μ.
Maxwell factors for gaseous 2.3.3.3-tetrafluoropropene and cis-1.3.3.3-tetrafluoropropene at zero density
Authors: Tsvetkov O B , Laptev Yu A , Prostorova A O , Vinzarevich A V
Published: November 2019

In this study we focused on the Maxwell factor of fluorinated propene isomers 2.3.3.3-tetrafluoropropene and cis-1.3.3.3-tetrafluoropropene last years receiving considerable attention as the next generation of refrigerants. Fluorinated propene isomers contain carboncarbon double bound. The advantage of both refrigerants is a low global warming potential value of 4 and 6 respectively. This paper deals with the temperature dependence of thermal conductivity in the limit of zero density for dilute gases. A theoretically based correlation formalism has been examined according to the kinetic theory of Mason–Monchik–Parker using a set of trial functions and related to the translational and integral effective collisions that incorporate the information concerning intermolecular pair potential and binary collisions. The results have correlated using the Maxwell factor. The analysis of quantities for practical purposes which are related to the thermal conductivity and viscosity has been made.
Thermodynamic assessment, screening and trade-offs in alternative working fluids selection for refrigeration, heat pumping and organic Rankine cycles
Authors: Mitropov V V , Tsvetkov O B , Laptev Yu A , Babich A Yu
Published: November 2019

Global warming and ozone depletion are leading effects attaching the consideration of environmental organizations. Conversion to alternative hydrofluorocarbons (HFC) refrigerants without chlorine atoms progressed over the last two decades. However recently because of the significant global warming impact of HFCs the hydrofluoroolefins (HFOs) were proposed as new generation alternative refrigerants. This article discussed fluorinated propene based isomers, summarizes refrigerant numbering scheme, flammability, fundamental parameters and thermodynamic properties of isomers containing five-, four- and three-fluorine atoms respectively. In the present study evaluated the refrigerant performance in an idealized vapor compression refrigeration cycle. Presented HFC and HFO blends as non-flammable refrigerants with relatively low global warming potential values.
Fission fragments and energy spectra of primary electrons in a fissioning plasma
Authors: Shapiyeva A E , Kunakov S K , Son E E
Published: November 2019

Some isotopes like 3He, 23BUF6 gases irradiated by thermal neutron flux may produce partially ionized plasma with the presence of fast particles like protons, tritium or heavy fission fragments. If a sample with 3He gas sets in thermal neutron flux, the helium atoms may born highly energetic particles: protons and tritium nuclei, which create in their own turn primary electrons and their other successive generations.

In the present paper Boltzmann kinetic equation for plasma, created by volume source of ionization is developed and solved for special cases, like presence of external electric field, strong enough to cause Townsend ionization. The ways of possible existing of highly energetic electrons accelerated by strong electric field energy also thoroughly discussed. Statistical approach based on the Monte Carlo technique including definition of self-consistent electric field formed by boundary conditions and nuclear induced plasma internal properties coupled with direct Boltzmann formalism also was developed and discussed. Thus the outbreak or the time explosion of the energy distributions of all fast particle including primary and secondary electrons are calculated in the programming complex as a function of time from 10 ps to 10 ns and for different neutron flux pulses and neutrons homogeneous spatial distribution. Non-linear problems such as an electron–ion recombination and successive generation of secondary electrons and electron queues are solved by Monte Carlo technique and comprehensively described. Detailed calculations show that so called runaway electrons are not appearing in nuclear induced plasma and whatever strong external electric field applied, there is no way to supply them relativistic energy and create so called runaway electrons. The appearance of electrons with an energy around MeV is possible when electrons (beta electrons) are born within nucleus due to internuclear transformations of up and down quarks affected by neutrinos oscillations. It takes place in nuclear fission process provoked by neutrinos and antineutrinos Reines et al (1960 Phys. Rev. 117 159). Time dependent spectra of primary electrons as well as their successive generations are calculated and compared with existing experimental data and developed for nuclear induced Boltzmann kinetic equation solutions. It is also should be noted that the bremsstrahlung radiation or braking radiation can not be treated as a type of force (friction force). It is clear that the transformation of kinetic energy into electromagnetic energy is a unique phenomenon and if it exists while fast electron is stopping in the medium, then there should be the reversed process, when electron gains its kinetic energy from surrounding electric field.
Energy of intermolecular forces in liquid halogenalkanes and their binary mixtures
Authors: Neruchev Yu A , Korotkovskii V I , Ryshkova O S
Published: November 2019

The paper analyzes the relation that allows studying the peculiarities of intermolecular forces and the nature of the structure of condensed substances with an atom-atom interaction mechanism. The estimate of the energy of intermolecular forces of saturated hydrocarbons and their halogen-substituted according to the data on their thermophysical properties and data on the individual characteristics of atomic centers are presented. A formula for predicting the dispersion constants of halogen-alkanes and their binary mixtures that accordance with experimental data is proposed.
Experimental study of thermophysical properties of W-Re alloy at high temperatures
Authors: Senchenko V N , Belikov R S
Published: November 2019

This article presents data on thermophysical properties of a tungsten-rhenium alloy W-Re (27 at. % of Re) in the temperature range of 2400–3100 K. Data on the thermal expansion and specific electrical resistance of this substance at premelting region are obtained, and the emission spectra of the alloy are obtained at high temperatures.
Structure and properties of YBCO before and after the short-term exposure of the plasma flow
Authors: Rabadanova A E , Gadzhimagomedov S Kh , Palchaev D K , Gadzhiev M H , Ragimkhanov G B , Demirov N A
Published: November 2019

The results on the structure and electrical resistance of the porous YBa2Cu3O7–δ
nanoceramics before and after plasma treatment are shown. It is shown that after exposure to high-enthalpy argon plasma flow, the structural, stoichiometrical and superconducting properties in the volume of this ceramics change slightly. An amorphous layer forms on the surface, the mechanical strength of the inter-granular bonds of which becomes higher than for the material in the bulk.
Experimental determination of destruction of thermally unstable substances
Authors: Dzhapparov T A-G , Bazaev A R
Published: November 2019

Different methods of thermal stability determinations are reviewed. The process of thermal decomposition of aliphatic alcohols and their aqueous mixtures in the range of temperatures 583.15–663.15 K was studied using the method of isothermal pressure increasing in a closed system. The decomposition points (Td) alcohols dissolved in water are obtained depending on their concentration. The changes of thermal coefficients (isothermal coefficient of compressibility kT, coefficient of cubical expansion α and thermal coefficient of pressure β) and main thermodynamic properties (Cv
, Cp
, H, S, U, F, G) of studied mixtures depending on isothermal pressure increasing during the thermal decomposition of alcohols were calculated.
Effect of dynamic screening on the electron capture process in nonideal plasma
Authors: Shalenov E O , Seisembayeva M M , Dzhumagulova K N , Ramazanov T S
Published: November 2019

In this paper, the process of electron capture in nonideal plasma has been investigated. For this goal the Bohr-Lindhard method has been applied to obtain the electron capture cross section. All calculations have been done in the framework of the trajectories of incident electron near hydrogen ion (proton) obtained by the numerical simulation of the equations of motion. The effective interaction potential, which takes into account the static or dynamic screening effects at large distances and quantum diffraction effects at short distances, was used. The results of numerical calculations of the electron capture radius, differential and total cross section for different values of the density parameter and velocity are presented. It is shown that dynamic charge screening increases the capture cross sections in comparison with static screening.
Study of the absorption spectrum of the thin film of titanium monoxide in the mid-wavelength IR range
Authors: Skryabin A S , Vesnin V R , Tsygankov P A , Chirkov A Yu , Vlasov E Yu , Ostanko D A
Published: November 2019

The paper presents experimental study of IR absorbance of the thin TiO film (with the thickness of 600 nm) on the glass substrate. The titanium monoxide (TiO) film was prepared with the ion-beam scattering. The film was characterized by XRD, FTIR, SEM etc. IR absorption spectra for the film and the substrate were measured. It was shown that the average absorbanceĀof the pure glass substrate isĀ≈ 0.08 in the wavelength range λ = 2.5 … 15μm. For the TiO film it was obtained thatĀ≈ 0.38 in the same λ range.
Investigation of temperature dependence of drilling mud viscosity with silica nanoparticles addition
Authors: Pryazhnikov M I , Mikhienkova E I , Minakov A V , Rudyak V Ya
Published: November 2019

An experimental study on the effect of silica nanoparticles addition on the viscosity of water-based mud at different temperatures was carried out. The mass concentration of clay was 5%, and the nanoparticles concentration varied from 0.5wt% to 3wt%. The nanoparticle size was 10 nm. Viscosity coefficient measurements were carried out in a wide temperature range.
Experimental research on the thermal conductivity of the contact pads for electronic equipment
Authors: Sukhikh A A , Kuznetsov K I , Skorodumov S V
Published: November 2019

Currently, soft contact pads of foreign manufacturers of SIL-Pad, Gap-Pad and Bond-Play series are widely used to transfer heat flows in electronic equipment elements. Within the framework of import substitution programs, the technology of manufacturing analogs of heat-conducting gaskets from local raw materials is being developed. The main thermal property that determines the performance of gaskets is the thermal conductivity. The article describes the installation, technique and methods of conducting and processing the results of experiments developed for its determination. The analysis of the obtained experimental data is made.
Infrared system for thermal resistance measurement of microobjects
Authors: Senchenko V N , Konovalov P A , Kapustin D I , Ilichev M V
Published: November 2019

The original measuring system and method of temperature fields measuring of integrated circuits chips for controlling of thermal resistance between a chip and its case under production conditions is presented. The infrared system allows temperature measuring over the range (40-150)°C, and also allows to spot small gains of IC chips temperature around 1°C. The developed system based on infrared microbolometric matrix and allows controlling of integrated circuits chips temperature fields with the high spatial resolution up to 15 microns.
Purification of fused alumina by high temperature calcination in vacuum
Authors: Belyaev G E , Grigorenko A V , Vlaskin M S , Lipatova I A , Shkolnikov E I , Zhuk A Z
Published: November 2019

The aim of present study was the investigation of purification efficiency of industrial white fused alumina at high-temperature calcinations, in vacuum. Three powder samples of alumina with different initial purity and particle size distribution were studied. The impurities amount in the white fused alumina powder decreased by factor 10 after vacuum calcinations. White fused alumina samples were almost completely cleared of Na, Mg, K, Mn, Cu and Zn. The iron content in the studied samples decreased by factor 8–10. Comparison of the granulometric composition and specific surface area of samples, showed that samples look like sets of porous grains with the average sizes between 16–60 μm. In turn, porous grains are composed of dense micro-particles with a characteristic size of 0.4–0.7 μm. The specific surface area of grains lies in the range 2.8–3.3 cm2/g. Relatively high rate of purification takes place due to porous structure and high surface area of the samples.
The effect of phonon diffusion on heat transfer
Authors: Khvesyuk V I , Qiao W , Barinov A A
Published: November 2019

The work is devoted to the development of a tool that allows simulating diffusion in structures where phonons play the main role in the heat transfer (dielectrics, semi-conductors). It is shown that the nature of phonon interaction is fundamentally different from the interactions in classical gases. For the first time, a method for calculating the diffusion of phonons, that takes into account all the important features of their interaction with each other, is presented. A computer simulation of phonon diffusion for a silicon sample in a two-dimensional formulation was carried out. It is shown that the nature of phonon diffusion differs from the classical Brownian diffusion.
Modeling the alumina cleaning by means of high temperature evaporation into vacuum
Authors: Ivanov P P , Vlaskin M S , Zhuk A Z
Published: November 2019

Considering a porous granule to be an ensemble of solid micro-particles the mathematical model is developed for the high temperature vacuum cleaning of alumina from ferrous impurity. Three parts of the process are identified: the diffusion in solid, the evaporation into vacuum and the filtration through pores into outer space. The model found to be consistent with available experimental data. Analytical solutions on the level of solid micro-particles might be instrumental for the treatment of experimental data.
Deformation behaviour of aluminium nanocrystals under shock-wave loading
Authors: Vlasova A M
Published: November 2019

Nonequilibrium process of shock-wave loading of aluminum nanocrystals were investigated numerically under uniaxial stress conditions using molecular dynamics simulations (MD). Deformation curves, time dependence of strain rate and the change in potential energy were constructed. Calculated properties of aluminium using embedded atom interatomic potential are compared with each other. Relationship between the calculated characteristics are discussed. The behaviour of deformation curves for two different aluminium nanosrystals is explained. The problems of modeling the deformation hardening of aluminum nanocrystals are considered.
Interaction of methane with thermal carbon dioxide plasma obtained in the AC plasma torch
Authors: Subbotin D I , Popov V E , Safronov A A , Popov S D , Surov A V , Kuchina J A , Obraztsov N B , Serba E O , Nakonechny Gh V , Spodobin V A
Published: November 2019

The article discusses a new method for producing synthesis gas using an ac electric arc. The relationship between the electrical parameters and the energy characteristics of the process was established: with an increase in carbon dioxide concentration in the electrode zone, the hydrogen concentration increases. This leads to an increase in the plasma torch power, which can be used to adjust the chemical process.
Viscosity and density of vacuum oils for diffusion pumps
Authors: Sagdeev D I , Gabitov I R , Fomina M G , Alyaev V A , Minkin V S , Abdulagatov I M
Published: November 2019

Current paper represents the results of viscosity and density measurements of vacuum oils for diffusion vacuum pumps. Vacuum oil samples are represented by the following brands: VM-1S, LEYBONOL LVO 500 and Alcarin-D24. All the measurements have been carried out at atmospheric pressure: viscosity has been measured by the capillary method in the temperature range from 293 K to 373 K, and density has been measured by the pycnometer and hydrostatic weighing methods in the temperature range from 293 K to 473 K.
Isochoric heat capacity and PVT properties of n-heptane – water binary azeotropic system
Authors: Ibavov N V , Mirskaya V A , Nazarevich D A
Published: November 2019

The isochoric heat capacity and the pressure of n-heptane – water binary layering system were measured using the high-temperature adiabatic calorimeter-piezometer method. Characteristic properties of a change in the temperature dependences of the heat capacity and the pressure along the isochores were revealed in a region of phase transitions. These features allow for fixing the azeotropy state in the system and for estimation of the influence a polar component (water) on a change in the azeptrope state temperature.
Exhaust composition at laser ignition of combustible gas mixtures under controlled conditions
Authors: Anishchanka Y V , Loktionov E Y
Published: November 2019

One of the main advantages of laser ignition is the ability to ignite lean combustible mixtures, resulting in obvious economy and reduction of harmful emissions, primarily NOx. Experimental data on exhaust composition are presented in the literature very poorly. As a rule, the studies were not of a systematic nature, considered only very specific conditions of combustible mixtures exposure and composition (mainly methane-air), and were obtained for experimental piston engines, the design and operational features of which could significantly affect the result. We suggested that in order to obtain a starting point for further optimization, a study of exhaust composition should be carried out under conditions of minimal impact of the engine design. For this purpose, an experimental stand was created, which allows to investigate the laser ignition of combustible mixtures of different composition in wide pressures range. We studied the laser ignition of gas mixtures based on butane with fuel-air coefficients ϕ ∼ 0.8 – 1.2, in pressure range p ∼ 1 – 3 bar, ignited by radiation of the the nanosecond Nd:YAG laser. The exhaust composition was analyzed by O2, CH, CO, CO2, NOx. Correspondence of the obtained results known from other experimental and theoretical works is analyzed.
Interlaminar tensile strength for composite materials made by additive manufacturing
Authors: Paredes A C , Bohórquez O , Pertuz A , Rueda Y , González-Estrada O A
Published: November 2019

The low interlaminar tensile strength of fiber reinforced composite materials presents serious challenges in the design of structures with a considerable radius of curvature, which is commonly found in a wide range of fields such as aeronautics, civil engineering, maritime industry, energy industry, among others. The objective of the present research was to analyze the interlaminar tensile strength, in the interlaminar layer of a material composed of fiberglass as reinforcement in nylon matrix, using a curved beam elaborated by additive manufacturing. To achieve this, tests were carried out according to ASTM Standard, and to determine which parameters significantly influence the failure of the composite material, variations were made in the thickness of the test specimens, which were manufactured following the criteria of the standard. The results obtained allow the assessment of interlaminar tensile strength and specimen behavior after failure.
Shape optimization of a control arm produced by additive manufacturing with fiber reinforcement
Authors: Chacón Santamaría P A , Sierra A , González Estrada O A
Published: November 2019

Additive manufacturing makes possible to overcome the limitations of subtractive manufacturing and supposes a transformation with respect to the traditional processes, allowing to manufacture complex geometries by controlled deposition of material. In the automotive industry, the application of continuous fiber reinforcement, in combination with shape optimization for additive manufacturing, can produce parts with higher mechanical performance. This paper reports the shape optimization problem of a suspension control arm to be produced by additive manufacturing with fiber reinforcement, using finite element analysis. First, the current material, loading conditions and constraints to which the control arm is subjected were determined, considering its traditional design. Then, a numerical model of the part was developed considering its current material and shape to obtain the total deformation and von Mises stress distributions. Afterwards, the new material model was defined, and the shape optimization was performed with the goal of maximizing stiffness. Finally, the results from the optimization process were validated by manufacturing and testing the part.
Adhesive joints for composite materials produced by additive manufacturing
Authors: Casas Pulido A F , Bohórquez O , González-Estrada O A , Quiroga J , Pertuz A
Published: November 2019

Composite materials are joined in many occasions with adhesive joints due to the condition of the materials, the ease of repair, the loading conditions, the affectation by corrosion and chemical attacks. However, the efficiency of these bonding schemes is related to multiple factors, among them, the length and the width of the adhesion zone and the thickness of the adhesive. In this work, we analyze the factors associated with the surface contact of the substrates. We define a numerical model using the finite element method and study the parameters related to the physical condition, considering optimal results based on the data of the strength provided by the suppliers of adhesives.
Interlaminar tensile strength of the composite of African palm oil bunches rachis fibers and epoxy matrix
Authors: Pinto-Flórez R A , Bohórquez O , González-Estrada O A , Vasquez L , Pertuz A
Published: November 2019

The organic composite materials are very competitive due to their low density and good flexibility by design, suitable for certain working conditions such as installations where high mechanical strength at a low weight is required. Additionally, they contribute to the environment by taking advantage of organic components that are currently waste. The composite proposed in this work consists of an epoxy matrix reinforced with African palm rachis fibers. The specimens were manufactured under the manual rolling process due to the nature of the reinforcement. Moreover, the variation of the interlaminar tensile strength was investigated, using a four-point flexion testing and varying the thickness of the specimen in order to evaluate the feasibility of the organic reinforcement. The experimental analysis was performed with a curved beam geometry and low flexion.
Analysis of the adhesion of titanium and carbon-diamond coatings on 3D printed textured surfaces
Authors: Zapata A , V-Niño E D , Endrino J L , Fernández-Martínez I , Díaz Lantada A , Martinez M , Pertuz A
Published: November 2019

The importance of coatings in engineering has been predominant throughout the development of the new industrial era. The competitiveness of the field has led to the development of better materials that achieve superior properties. The purpose of this research is evaluating the adhesion to the surfaces coated by magnetron sputtering technique. The adherence quality of the deposited coatings on specimens was evaluated adhesion by scratch and indentation tests guided according to standards, using the Tribolab UMT at constant load. The results obtained allow validating of the additive manufacturing process as possible mechanicals applications.
Tensile mechanical properties of composite materials with continuous fiber produced by additive manufacturing
Authors: Sierra Nossa I , Bohórquez O , Pertuz A , Sánchez Acevedo H G , González-Estrada O A
Published: November 2019

Additive manufacturing of composites parts reinforced with continuous fibers is emerging as a versatile process, capable of producing complex computer-aided design models by fabricating parts adding material layer by layer. Fused deposition modelling using polymeric materials has been used to produce prototypes, with the constraint of the strength of the material. Recently, the use of continuous fiber reinforcement has provided an alternative for the production of load-bearing functional parts. Current international standards for the characterization of composite materials from mechanical tests are established for parts manufactured by conventional methods, such as, manual molding, injection or coatings. Moreover, the standards do not specify procedures for composite materials produced by additive manufacturing. The objective of this work is to evaluate the performance of the reinforced composite materials produced by additive manufacturing for tensile tests under ISO and ASTM standards, and compare the results in terms of the topology of the material configuration. Average values of the tensile strength for composite materials having a triangular nylon matrix reinforced with fiberglass were obtained within the range of 205 MPa to 234 MPa, with deformations no greater than 0.020 mm. These values are higher than the strength provided by additive manufacturing using materials such as polylactic acid and acrylonitrile butadiene styrene.