bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of Adaptive Class Assessment Based on Learning Management System for Electrical Engineering Expertise Program in Vocational School
Authors: Hadi S , Haryanto
Published: January 2021

This study aims to develop a classroom assessment tool that can be used in LMS-based adaptive assessment and test the appropriateness of the classroom assessment tool. This research is development research. The development research model used is the scale construction process with the following steps: articulate construct and context, choose response format and assemble initial item pool, collect data from respondents, examine psychometric properties and quality so that a final scale is obtained. Respondents of this study were experts who assessed the validation and students of the Vocational High School of Electrical Power Installation Engineering Expertise. The data analysis technique used is instrument analysis using classical test theory and descriptive statistics. The results of the study are: the construct of selected class assessment tools is easy to implement in a computer program. Multiple choice questions with 5 alternative answers. The attitude questionnaire is made in the form of a case assessment with 4 alternative answers, while the observation guidelines are made in the form of a short entry with numbers between 1 and 4. The questions developed have 60 items. Items with less validity are 0, moderate there are 55, and high is 5 with Alpha reliability of 0.934. The attitude questionnaire developed consists of 8 items. The items with less validity are 0, 6, and 2 with high Alpha reliability of 0.731. The observation guide developed contains 16 points of observation. Items with less validity are 0, the medium is 15, and high is 1.
Diagnosis of Diabetes Mellitus Based on 11 Health Risk Factors using Backpropagation
Authors: Arifin F , Adhana R F , Shabrina Yois N A , Khairudin M , Ma’arof N N M I
Published: January 2021

Diabetes Mellitus (DM) is a non-communicable disease and is a severe chronic illness. Early detection of DM is one way to detect the possibility of someone getting DM. This application was made to determine the accuracy of the diagnosis of DM using backpropagation ANN. There are 11 risk factors used, namely gender, smoker or not, heredity, systolic blood pressure, diastolic blood pressure, total cholesterol levels, HDL (High-Density Lipoprotein) levels, LDL (Low-Density Lipoprotein) levels, triglyceride levels, BMI (Body Mass Index), and HBA1c levels (Hemoglobin A1c). Risk factors are taken based on medical records of DM patients and data on healthy people. The training and testing of artificial neural networks showed promising results for the suitability of network output and desired targets with a correlation coefficient of 0.98043. The results of testing showed promising results for network output and target match desired with a correlation coefficient of 0.97894.
The Effects of Vertical and Horizontal Distance on The Performance of QR Code Detection System
Authors: Hakim M L , Yatmono S , Nugraha A C , Khairudin M
Published: January 2021

The development of image processing science is needed to solve problems that are often faced by humans, especially in the field of computer vision. One application of the image processing system is on a package delivery mission during the Covid-19 pandemic. Drones are used to send packages by detecting the presence of Qr Code to determine the point of delivery location. In this study, tests will be carried out on the maximum distance (vertical and horizontal) that can be detected by the Qr Code detection system and the length of time to detect the presence of the Qr Code (time spent). The test shows that the greater the data collection distance (vertical and horizontal), the longer the system detects the presence of the Qr Code. The maximum horizontal distance that the Qr Code can detect is 155 cm, while the vertical distance is 115 cm. The detection distance at vertical is smaller than horizontal because the vertical distance is affected by the field of view (FoV).
The Development of Android-based Control System for Reinforcing the Electronic Control Subject
Authors: Hariyanto D , Mustaqim I , Maruanaya R F
Published: January 2021

The advancement of technology has brought the control system technology recently to be more precise, stable, and reliable. It is also possible to utilize the sophisticated hardware embedded in the smartphone for controlling or monitoring system through the external modules. This study aimed to develop an Android-based control system that can be used to reinforce the students’ competence, particularly in the Electronic Control subject. The method used in this study was a linear sequential model that comprises analysis, design, coding, and testing. A total number of nine items of functional testing has been conducted, and the results revealed that the prototype control system could successfully react as designed. Nevertheless, the one that should be considered in the future study is the compatibility issue between the external controlled hardware and the smartphone.
Development of Power Electronic Practicum Units for Vocational Education
Authors: Prianto E , Sunomo  , Maryadi T H T
Published: January 2021

The purpose of this research is to develop a Power Electronics practicum unit in the Department of Electrical Engineering Education, Faculty of Engineering, YSU, so that it is suitable and feasible to be applied in vocational education learning by considering the safety aspects of the components and their users. The development includes a three-phase AC source voltage drop from 45 volts to 24 volts per phase, load replacement, the use of up and down voltage converters with greater current capability, and a direct voltage power supply without a transformer switching model. The method used is research & development with technical tests for each part of the module according to the purpose of setting up the practicum unit. The research results were obtained; the power supply with a 24 volt AC source is able to supply a current of 3.63 amperes at a direct voltage of 20 volts with a voltage drop of 0.5 volts, a direct voltage lowering converter is able to change the voltage from 15 volts to 6 volts at a current of 3.66 amperes, with a voltage drop of 0.13 volts. A direct voltage booster converter is able to convert a voltage of 15 volts from 1.78 amperes to 25 volts with a voltage drop of 0.1 volts. The four-pole three-phase motor can be controlled via the TRIAC from zero rotation to maximum rotation, the protection system is capable of breaking the fuse instantaneously in the event of a faulty connection from phase-neutral to phase, followed by disconnection of the 24-volt three-phase AC power source within one second.
Measurement of the radiation environment of the ATLAS cavern in 2017–2018 with ATLAS-GaAsPix detectors
Authors: Boyko I. , Burian P. , Campbell M. , Chelkov G. , Cherepanova E. , Girolamo B. Di , Gongadze A. , Janecek J. , Kharchenko D. , Kruchonak U. , Lapkin A. , Sierra Y. Mora , Nessi M. , Pontecorvo L. , Pospisil S. , Rastorguev D. , Rozhkov V. , Smolyanskiy P. , Suk M. , Stekl I. , Tolbanov O. , Tyazhev A. , Zarubin A.
Published: January 2021

A network of ten GaAs:Cr semiconductor Timepix detectors with GaAs:Cr sensors was installed in the ATLAS cavern at CERN's LHC during the shutdown periods 2015–2016 and 2016–2017 in the framework of a cooperation between ATLAS and the Medipix2 Collaboration. The purpose was to augment the existing system of measuring and characterising the radiation environment in the ATLAS cavern that is based on ATLAS-TPX devices with pixelated silicon sensors. The detectors were in continuous operation during 13 TeV proton-proton collisions in 2017–2018. Data were recorded during proton-proton bunch crossings, and during times without bunch crossings (LHC physics runs) as well as between the physics runs. The overall level of particle radiation as well as the ratio between neutral and charged particles were measured. The detectors recorded all interactions of charge particles, neutrons and photons in GaAs sensors, in which the signal was higher than 6.5 keV in individual pixels. This made it possible to register clusters (tracks) of individual radiation particles interacting in the detectors sensors. During LHC beam-beam collisions, these were all particles represented in the radiation field. In the periods without beam-beam collisions, these were photons and electrons resulting from radioactivity induced during previous collisions in GaAs detectors and in surrounding construction materials, namely by neutrons.
Future regulated flows of the Colorado River in Grand Canyon foretell decreased areal extent of sediment and increases in riparian vegetation
Authors: Kasprak Alan , Sankey Joel B , Butterfield Bradley J
Published: January 2021

Sediment transfer, or connectivity, by aeolian processes between channel-proximal and upland deposits in river valleys is important for the maintenance of river corridor biophysical characteristics. In regulated river systems, dams control the magnitude and duration of discharge. Alterations to the flow regime driven by dams that increase the inundation duration of sediment, or which drive the encroachment of vegetation into areas formerly composed of labile sediment and result in channel narrowing, may reduce sediment transfer from near-channel deposits to uplands via aeolian processes. Employing spatial methods developed by Kasprak et al (2018 Prog. Phys. Geogr.), here we use data describing the areal extent of bare (i.e. subaerially exposed and non-vegetated) sediment along 168 km of the Colorado River downstream from Glen Canyon Dam in Grand Canyon, USA, in conjunction with inundation extent modeling to forecast how future flows of this highly regulated river will drive changes in the areal extent of sediment available for aeolian transport. We also compare modern bare sediment area to that which presumably would have existed under pre-dam hydrographs. Over the next two decades, the planned flow regime from Glen Canyon Dam will result in slight decreases in bare sediment area (−1%) on an annual scale. This is in contrast to pre-dam years, when unregulated low flows led to marked increases in bare sediment area as compared to the current discharge regime. Our findings also indicate that ∼75% of bare sediment in the study reach is inundated continuously at present, owing to increased baseflows in the post-dam flow regime; consequently, any reductions in flows below modern-day low discharges have the potential to expose large areas of bare sediment. We use vegetation modeling to quantify areas susceptible to vegetation encroachment under future flows, finding that 80% of bare sediment area is suitable for colonization by invasive tamarisk under the current flow regime. Our findings imply that the Colorado River in Grand Canyon, a system marked by widespread erosion of sediment resources and encroachment of riparian vegetation in the post-dam period, is likely to continue to see decreasing bare sediment extent over the coming decades in the absence of direct intervention through flow regime modification or widespread vegetation removal.
Have food supply chain policies improved forest conservation and rural livelihoods? A systematic review
Authors: Garrett Rachael D , Levy Samuel A , Gollnow Florian , Hodel Leonie , Rueda Ximena
Published: January 2021

To address concerns about the negative impacts of food supply chains in forest regions, a growing number of companies have adopted policies to influence their suppliers’ behaviors. With a focus on forest-risk food supply chains, we provide a systematic review of the conservation and livelihood outcomes of the mechanisms that companies use to implement their forest-focused supply chain policies (FSPs)—certifications, codes of conduct, and market exclusion mechanisms. More than half of the 37 cases that rigorously measure the outcomes of FSP implementation mechanisms find additional conservation and livelihood benefits resulting from the policies. Positive livelihood outcomes are more common than conservation additionality and most often pertain to improvements in farm income through increases in crop yields on coffee and cocoa farms that have adopted certifications or codes of conduct. However, in some cases certifications lead to a reduction in net household income as farmers increasingly specialize in the certified commodity and spend more on food purchases. Among the five cases that examine conservation and livelihoods simultaneously, there is no evidence of tradeoffs or synergies—most often an improvement in one type of outcome is associated with no change in the other. Interactions with public conservation and agricultural policies influence the conservation gains achieved by all mechanisms, while the marketing attributes of cooperatives and buying companies play a large role in determining the livelihood outcomes associated with certification. Compliance with the forest requirements of FSP implementation mechanisms is high, but challenges to geospatial monitoring and land use related selection biases limit the overall benefits of these policies. Given the highly variable methods and limited evidence base, additional rigorous research across a greater variety of contexts is urgently needed to better understand if and when FSPs can be successful in achieving synergies between conservation and livelihoods.
Critical level statistics at the many-body localization transition region
Authors: Rao Wen-Jia
Published: January 2021

We study the critical level statistics at the many-body localization (MBL) transition region in random spin systems. By employing the inter-sample randomness as indicator, we manage to locate the MBL transition point in both orthogonal and unitary models. We further count the nth order gap ratio distributions at the transition region up to n = 4, and find they fit well with the short-range plasma model with inverse temperature β = 1 for orthogonal model and β = 2 for unitary. These critical level statistics are argued to be universal by comparing results from systems both with and without total S

z
conservation. We also point out that these critical distributions can emerge from the spectrum of a Poisson ensemble, which indicates the thermal-MBL transition point is more affected by the MBL phase rather than thermal phase.
Closest separable state when measured by a quasi-relative entropy
Authors: Vershynina Anna
Published: January 2021

It is well known that for pure states the relative entropy of entanglement is equal to the reduced entropy, and the closest separable state is explicitly known as well. The same holds for Renyi relative entropy per recent results. We ask the same question for a quasi-relative entropy of entanglement, which is an entanglement measure defined as the minimum distance to the set of separable state, when the distance is measured by the quasi-relative entropy. First, we consider a maximally entangled state, and show that the closest separable state is the same for any quasi-relative entropy as for the relative entropy of entanglement. Then, we show that this also holds for a certain class of functions and any pure state. And at last, we consider any pure state on two qubit systems and a large class of operator convex function. For these, we find the closest separable state, which may not be the same one as for the relative entropy of entanglement.
Size-dependent phase stability of silver nanoparticles
Authors: Murzakaev A M
Published: January 2021

A comparative analysis of the structure of silver nanoparticles obtained by chemical synthesis (citrate method) and electrical explosion of wires is carried out. The structure, phase composition, lattice parameters of silver nanoparticles with sizes from 2 to 50 nm were studied by electron diffraction and high-resolution transmission electron microscopy. All silver nanoparticles obtained by the chemical method have only a cubic structure. Silver nanoparticles obtained by the physical method have cubic and hexagonal structures. The existence of the hexagonal phase under normal conditions is explained by the quenching effect. The lattice parameters of the cubic phase of Ag NPs within the experimental determination error (± 0.01 nm), synthesized by the chemical method and by the method electrical explosion of wires do not differ from each other.
Microstructure and properties of solid state joints of titanium sheets produced by ultrasonic welding
Authors: Mukhametgalina A A , Murzinova M A , Nazarov A A
Published: January 2021

The results of the study on the microstructure and properties of solid state joints of titanium sheets obtained by ultrasonic welding (USW) with frequency 20 kHz and vibration amplitude 20 μm during 2 and 3 s under a 6 kN clamping force are presented. The thermo-mechanically affected zone is observed along the defect-free weld line (joint). It was found that the length and width of this zone increased with the welding time. In the thermo-mechanically affected zone, a significant grain growth takes place, a change in the texture is observed and maxima near 60° and 90° in the grain boundary misorientation distributions appear. The maximum lap shear failure load of the joints obtained by USW of 2 and 3 s durations are 1998±122 and 2506±226 N, respectively. There is a change in the failure mode from interface debonding after 2 s USW to nugget pull-out for the welding time of 3 s.
Ultrasonic welding of ultrafine grained nickel
Authors: Shayakhmetova E R , Nazarov A A , Samigullina A A , Zhilyaev A P
Published: January 2021

Solid state joints were obtained for the first time by ultrasonic welding (USW) of ultrafine-grained (UFG) thin disks of Ni processed by high pressure torsion (HPT). Samples of two types were studied: the ones for lap shear mechanical tests were prepared by joining two disks superimposed on each other under static loads of 4.5 and 6.0 kN, and the other type samples for structural characterization were obtained by sequential welding (consolidation) of four disks. The welding time for both type samples was equal to 1 s. The structure of consolidated samples was studied in their cross section by SEM, EBSD analysis, and also their Vickers microhardness was measured.
Influence of superplastic deformation on the quality of solid-phase joints obtained by welding of crystalline alloys
Authors: Lutfullin R Ya , Mukhametrahimov M Kh , Galieva E V
Published: January 2021

Pressure welding using the phenomenon of structural superplasticity is a relatively new technological method based on the additive principle of forming parts. The problem of the quality of a solid-phase joint, which is well studied for superplastic titanium alloys, requires a verification of the versatility of the approaches used to solve it for heat-resistant nickel alloys, as well as for welding of dissimilar crystalline materials. The possibility of reducing the temperature of pressure welding by using low-temperature superplasticity of ultrafine-grained (UFG) crystalline alloys is considered.
Accumulative high-pressure torsion of steel 316 and β-Ti alloy
Authors: Gunderov D V , Khasanova D A , Astanin V V , Churakova A A , Ramazanov I A , Prokoshkin S D , Sheremetyev V A
Published: January 2021

As revealed by studies, in the process of high-pressure torsion of hard or work-hardenable metals and alloys, including bulk metallic glasses, the actual produced strain is much smaller than the expected one. The authors proposed a new technique called “accumulative high-pressure torsion” for producing high strains in hard materials, including bulk metallic glasses.
Computer simulation of friction stir processing of plate from 2024 aluminum alloy
Authors: Akhunova A Kh , Imayev M F , Valeeva A Kh
Published: January 2021

In the present work, three-dimensional finite element modeling of the friction stir processing of a 3-mm-thick 2024 aluminum alloy plates using DEFORM-3D software product has been carried out. The optimal pin length was determined based on the calculation of the distribution of effective deformation, temperature, and displacement of material points. Numerical modeling was done on pins in the form of a cylinder with a diameter of 2 mm and a length of l = 1.6, 1.8, 2.0, and 2.2 mm. Friction stir processing was carried out at a traversing rate of 2 mm/s, a tool rotation rate of 1000 rpm, and an axial force of 20 kN. The material behavior of the sheet was described using the Johnson-Cook model included in the standard DEFORM-3D library. The results showed that the most preferable under the considered processing conditions is a pin with a length of 2.0 mm because it allows one to obtain the widest and most symmetrical regions of intense heating and deformation.
Finite-element modeling of the stress-strain state in disk-shaft type parts from dissimilar Ni-based alloys
Authors: Akhunova A Kh , Valitov V A , Galieva E V
Published: January 2021

Finite element modeling of the stress-strain state of disk-shaft type parts of gas turbine engines during pressure welding has been made. Pressure welding was carried out by three schemes of deformation of a disk and/or a shaft. In Scheme 1, the shaft was inserted into the disk by setting the displacement of the upper die, in Scheme 2 simultaneous action of a die on the upper end surface of the disk and shaft was set, and in Scheme 3 the shaft was inserted into the disk by setting the displacement of the die, then the action of the die on the upper end surface of the disk was set. Computer simulation is performed using the DEFORM-2D software package. The deformable nickel base alloys EP975 and EK79 were taken as materials for a disk and a shaft, respectively. The results of computer simulation have shown that for increasing quality of the welded joint between the disk and the shaft it is preferable to use pressure welding which is carried out with a combination of sequence actions on the shaft and disk, since in this case an effective summarized compressive stresses and radial strain were achieved which leads to an increase of the joint quality.
Protective PEO-coatings on titanium shape memory alloy for medical implants
Authors: Shechtman S R , Farrakhov R G , Ramazanov I A , Sheremetyev V A , Parfenov E V
Published: January 2021

The use of titanium shape memory alloy Ti-18Zr-15Nb with promising coatings for the manufacture of medical implants is considered. In this paper, we examined plasma electrolytic oxidation (PEO) in a pulsed bipolar mode with different frequencies to protect the surface from the aggressive environment of the human body.. Two frequencies of 300 and 1000 Hz were used. The results of SEM, EDS, XRD analysis, and electrochemical tests of the coatings were discussed. As a result of comparison, it was shown that carrying out the PEO process at 1000 Hz provides the formation of a more uniform coating with higher quality than the coating obtained at 300 Hz.
Evolution of particles of secondary phases in alloys of the Cu-Cr-Zr system in the state of a supersaturated solid solution in the process of deformation-heat treatment
Authors: Chembarisova R G , Galaktionova A V
Published: January 2021

In this work, the evolution of particles of secondary phases in the process of equal-channel angular pressing and subsequent heat treatment of the Cu-1.0 wt.% Cr-0.7 wt.% Zr-0.2 wt.% Al alloy, preliminarily subjected to quenching from the pre-melting temperature, is studied. It is shown that in the process of deformation of the samples, partial dissolution of small particles of the secondary phases occurs. As a result of the subsequent aging, the Cr and Al atoms that have passed into the solution are again separated into small particles. Additionally, there was a partial separation of Cr atoms from the solid solution into small particles of chromium.
Corrosion resistance of ultrafine-grained pseudo-α titanium alloy PT-3V
Authors: Nokhrin A V , Kopylov V I , Andreev P V , Chuvil’deev V N , Likhnitsckii C V , Chegurov M K , Murashov A A , Gudz’ D A
Published: January 2021

Ultrafine-grained (UFG) samples of PT-3V pseudo-α titanium alloy were subjected to diffusion welding through spark plasma sintering. It has been shown that the destruction of welded UFG samples under hot salt corrosion (HSC) is two-staged: first, intercrystalline corrosion (ICC) is manifested, which then graduates to pitting corrosion. It has been established that the corrosion resistance of the weld joints is determined by the concentration of vanadium at the grain boundaries, the size and volume ratio of the β-phase particles, and the presence of pores in the weld joints. It has been shown that welded UFG samples possess a higher hardness and resistance to ICC than coarse-grained samples.
Theoretical estimation, simulation and experimental evaluation of deformation-induced heating of magnesium during lateral extrusion
Authors: Komkova D A , Zamaraeva J V , Loginov Yu N , Koshevoy P S , Sokolov A L , Volkov A Yu
Published: January 2021

Theoretical estimation, computer simulation and experiment were performed to evaluate temperature of the deformation heating of magnesium during severe plastic deformation by lateral extrusion method. The simulation of the deformation process was carried out by DEFORM-3D. Experimental temperature measurement of magnesium deformation-induced heating at the deformation zone was made. According to the simulation, temperature of the magnesium billet has reached 114°C during deformation. Experimental results showed that the maximum temperature of deformation heating of the material is ∼140°C.
Work function of chemical compounds of aluminum-magnesium system
Authors: Khisamov R Kh , Kistanov A A , Nazarov K S , Shayakhmetov R U , Korznikova G F , Yumaguzin Yu M , Dmitriev S V , Mulyukov R R
Published: January 2021

For pure metals aluminum and magnesium and for chemical compounds Al3Mg, Al2Mg, AlMg and AlMg3 with crystallographic orientations (100), (110) and (111) the work function is calculated from the first principles in the framework of the density functional theory. It is shown that the dependence of the work function on the magnesium concentration in aluminium is nonlinear. The reasons for the work function differences of chemical compounds depending on the crystallographic orientation are analysed.
Mass transfer in platinum by crowdion clusters initiated by the impact of a Pt2 molecule
Authors: Shepelev I A , Dmitriev S V , Morkina A Yu , Fomin S Yu , Korznikova E A
Published: January 2021

This work presents a molecular dynamics study of the propagation scenario of the crowdion complex initiated in the platinum crystal by means of atom or molecule bombardment with parallel and non-parallel orientations. The obtained results enable to conclude that the crowdion initiated by the Pt2 molecule bombardment is significantly more effective for the mass transfer comparing to the crowdion excited by the single atom impact. It was detected that the atoms involved in the crowdion motion bear a vibrational mode with the frequency above the phonon spectrum. The obtained results contribute to the understanding of the mechanisms of mass transfer under equilibrium conditions.
X-ray analysis of the Cu-Zn alloys system subjected to ECAP and subsequent rolling
Authors: Zaynullina L I , Alexandrov I V
Published: January 2021

The results of X-ray diffraction analysis aimed to reveal the features of the evolution of microstructure parameters as a result of equal-channel-angular pressing and subsequent flat rolling of the Cu-Zn alloys system with different Zn (10 and 30 wt. %) contents and, as a result, different stacking fault energies are presented.
Mechanical properties and structure of welded joints of VT6 alloy through nanocrystalline interlayer of VT22
Authors: Mukhametrakhimov M
Published: January 2021

Experimental studies of the solid-phase weldability of the VT6 alloy through an interlayer of VT22 alloy in the temperature range of the low-temperature superplasticity (T=820 °C) of one of the elements to be joined have been carried out. Welding of dissimilar titanium alloys allows us to significantly reduce the temperature of pressure welding due to the use of alloys alloyed with different elements. The VT22 with nanocrystalline structure interlayer allows localizing deformation at the junction zone due to a significant difference between the values of the interlayer flow stress and welded billets. To improve the mechanical properties, the welds were heat-treated at T=900 °C. The optimal properties of welded joints are increased after the heat treatment of researched titanium alloys. This leads to the activation of diffusion processes and the disappearance of micropores. Thus, it can be concluded, that getting dissimilar titanium alloys high-quality solid-phase joint depends not only on the size of the interlayer grains but also on the material in the joint zone chemical and phase composition.
Silver nanoparticles formation over Ti-Zr-Nb alloy via polyol synthesis
Authors: Teplyakova T O , Popova D V , Prokoshkin S D , Konopatsky A S
Published: January 2021

Ag nanoparticles (AgNPs) were formed over the surface of novel superelastic Ti-Zr-Nb alloy via polyol synthesis at room temperature. Two synthesis media were used for AgNPs formation: ethylene glycol (EG) and polyethylene glycol (PEG-400). AgNPs formation rate in different polyols was evaluated by UV-VIS spectroscopy. Based on the obtained results higher formation rate was ascribed to PEG-400. Morphology of the material’s surface, as well as chemical composition, were analyzed by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was demonstrated that the usage of PEG-400 as synthesis media facilitates the formation of more monodisperse AgNPs evenly distributed over the alloy’s surface.
Features of structure and physical and mechanical properties of metal-ceramic composite material depending on the content of boron nitride
Authors: Bolshakov B O , Smyslov A M
Published: January 2021

In this paper, the problem of structure formation in powder compacts of PCh13M2-BN obtained by solid-phase sintering is considered. A phenomenological model of the formation of regions with increased concentration of ceramic BN particles in the volume of compacts is developed. The influence of the concentration of boron nitride in the initial charge on physical and mechanical characteristics of compacts is determined.
Copper oxide nanowhiskers: structure, growth mechanisms, and associated stresses
Authors: Podlesnov E , Churkunova N V , Dorogov M V
Published: January 2021

A detailed study of the structure of nanowhiskers and the processes accompanying their growth during thermal oxidation are presented. The structure of nanowhiskers is studied by scanning and transmission electron microscopy and X-ray diffraction. The role of internal stresses in the substrate on the growth of nanowhiskers is shown, and the stress state for various configurations of the copper/copper oxide system is calculated. The sorption, catalytic, electrochemical, and mechanical properties of oxide nanowhiskers are described. The areas of the practical application of copper oxide nanowhiskers such as water purification systems and lithium batteries are shown.
Research and features of preliminary graphitizing processing of melt of iron with silicon carbide on the structure and properties of cast iron castings
Authors: Boldyrev D.A. , Platov S.I. , Urtsev N.V. , Terentyev D.V. , Latypov O.R.
Published: January 2021

The materials used for preliminary graphitizing treatment of cast iron melt (pre-modification), of which silicon carbide has the greatest technical and economic advantage, are considered. The features of the graphitizing effect of silicon carbide during the preparation of a gray cast iron melt on its structure and properties in standard cylindrical samples and clutch plate castings are analyzed. It is shown that its graphitizing effect on the cast iron melt begins to partially manifest itself already at the stage of introduction into the furnace and enhances the action of the main graphitizing modifier during subsequent ladle treatment as a result of a decrease in the content of interdendritic graphite in the microstructure.
Superplastic forming of hemispheres out of AZ61 magnesium alloy
Authors: Kruglov A A , Tulupova O P , Olimpieva N V , Ganieva V R , Enikeev F U
Published: January 2021

The paper proposes a method for calculating the rheological parameters included in the standard power ratio of superplasticity based on the results of test forming of hemispheres using a cylindrical matrix. The method takes into account the value of the entry radius of the matrix. The analytical model of the process is developed based on the main assumptions of the theory of thin shells, the finite element model is executed using the ANSYS10 ED software package. As compared to the traditional approach, the proposed method allows improving the modeling accuracy with an error less than 1%, not only for the forming time, but also for the thickness at the pole of the dome.
Structural and phase transformations in austenitic chromium-nickel steels during nanostructuring frictional treatment
Authors: Skorynina P A , Makarov A V , Volkova E G , Osintseva A L
Published: January 2021

The parameters of the structure and phase composition of austenitic structural steels subjected to frictional treatment with a sliding indenter were studied by X-ray diffraction and transmission electron microscopy. It has been found that the strengthening of deformation-stable austenitic steel was due to the formation of finely divided austenite, with the intensification of the grain-boundary and dislocation strengthening mechanisms. Additional strengthening of metastable austenitic steel was due to the formation in the surface layer of about 70% of the volume fraction of nanocrystalline strain-induced martensite. It is proposed to use nanostructuring frictional pretreatment as a promising method for hardening austenitic structural steels before the subsequent application of superhard, dead-hard, and heat-resistant nanocomposite coatings.
Influence of composition nonstoichiometry and ordering effects on the properties of ferroelectric ceramics based on lead magnoniobate
Authors: Lebedinskaya A R , Rudskaya A G
Published: January 2021

The effects of violation of the stoichiometry of lead magnoniobate in the preparation of compositions (1-x)PbMg1/3Nb2/3O3 – xPbMg1/2Nb1/2O2,75 with a step of 0.1 and 0≤x≤1 have been studied by X-ray diffraction methods. Differences in the unit cell parameters of the ferroelectric ceramic samples of the composition under study were found. It was shown that the effect of ordering of different types of atoms in the cells, leading to the formation of a superstructure and a doubling of the lattice period, was not observed in any of the samples. . Measurements of the dielectric constant of the synthesized samples and the tangent of the dielectric loss angle showed a violation of the Curie-Weiss law, which indicates the diffusion of the phase transition.
Superplastic behavior of a nickel-base superalloy containing topologically close-packed phases
Authors: Mukhtarov S K , Ganeev A A , Shakhov R V , Imayev V M , Logunov A V
Published: January 2021

Superplastic behaviour of a polycrystalline nickel-base superalloy Ni-47(Cr,Co,W,Al,Ta,Hf)-0.2(C,B) (wt.%) in the fine-grained condition obtained via thermomechanical treatment (TMT) has been studied. TMT transformed a coarse-grained as-cast structure into a homogeneous fine-grained one. Both the initial as-cast and the thermomechanically treated conditions contained not only the matrix γ phase, the hardening γ’ phase and carbides but also topologically close-packed (TCP) phases. In spite of the presence of the TCP phases, the superalloy in the fine-grained condition demonstrated superplastic properties (δ>300% and low flow stresses) at subsolvus temperatures. Superplastic deformation led to some refinement and alignment of the TCP phase particles along the tensile axis.
Influence of structural state on corrosion behaviour of bearing steel 110C-18Cr-Mo
Authors: Abramova M M , Tuktamysheva E R , Saburova Yu B , Enikeev N A
Published: January 2021

The paper report on the studies of the effect of severe plastic deformation on the structure and properties, including the corrosion behavior, of 110C-18Cr-Mo bearing steel. Various structural states were formed by the methods of severe plastic deformation (SPD) and subsequent heat treatment. It is shown that SPD and subsequent heat treatment lead to the formation of a homogeneous structure with a uniform distribution of carbides. In this case, heat treatment leads to a reduction of the volume fraction of carbides and an increase in the microhardness of the samples. Steel subjected to SPD demonstrates a decrease in the corrosion rate in one-molar solutions of salt and sodium hydroxide. Subsequent heat treatment leads to an additional decrease in the corrosion rate.
Interaction of supersonic 2-crowdions in fcc platinum
Authors: Bayazitov A M , Korznikova E A , Semenov A S , Borisov D I , Dmitriev S V
Published: January 2021

In metals subjected to ion implantation or irradiation, mass transfer by supersonic crowdion clusters takes place. The interaction between supersonic 2-crowdions moving in parallel close-packed atomic rows has been studied only in 2D Morse lattice and here it is analysed with the use of molecular dynamics simulations in fcc platinum.
Behavior of the mechanical system composed of highly deformable structural elements
Authors: Abdullina D U , Rysaeva L Kh , Korznikova E A , Dmitriev S V
Published: January 2021

Carbon nanotubes (CNTs) are attractive for many applications because they possess a unique combination of mechanical and physical properties. Horizontally aligned CNT bundles under lateral compression behave as an elastic body with highly deformable elements, since their cross sections can collapse. Mechanical properties of such systems is poorly investigated in spite of the fact that they are promising for vibration and shock protection. Here we use a chain model with a reduced number of degrees of freedom in order to study the behaviour of a CNT bundle under uniaxial and biaxial lateral compression. Stress-strain curves are obtained and evolution of the CNT bundle structure is analyzed.
Comparative analysis of fine-grained structure formation in an Al-Zn-Mg-Cu alloy during multidirectional isothermal forging and uniaxial compression
Authors: Sitdikov O , Sakai T
Published: January 2021

A comparative study of the mechanical behavior and microstructural evolution in a cast coarse-grained 7475 Al alloy during uniaxial compression and multidirectional forging at 490°C and 10–4 s–1 was performed. It was shown that high-temperature deformation of the alloy led to grain refinement accompanied by strain softening. At similar processing conditions, the deformation path provided by multidirectional forging was found to be more favorable for grain refinement and strain softening than that of uniaxial compression.
Methods of controlling mechanical behavior of layered titanium material under impact loading
Authors: Sarkeeva A A , Kruglov A A , Lutfullin R Ya
Published: January 2021

The results of studies on the mechanical behavior of a Ti-6Al-4V laminated material obtained by diffusion welding are analyzed. It is shown that the impact behavior of the layered material depends on many factors including the interface defects, the orientation of the notch tip relative to interface, the number and microstructural state of the layers and their crystallographic texture.
Determination of Standard Oxygen Transfer Rate in Venturi Aeration System
Authors: Yadav Anamika , Kumar Avinash , Sarkar Sudipto
Published: January 2021

The oxygen transfer is the process of atmospheric oxygen diffusion from a gas stage to a liquid stage in the form of dissolved oxygen (DO). The previous research works have successfully proven that the DO concentration level effortlessly rises by adopting a venturi as an aeration method in aquatic bodies. Present experimental study was conducted on laboratory scale aeration tank with two different sizes of venturi (40 and 80 mm throat length). The objective of the current study was to determine the oxygen transfer coefficient at different discharge rates through venturi aeration system. The system was operated with three different discharges of 0.50, 0.58 and 0.67 liter/second (l/s) to circulate 200 liter volume of water, was aimed for circulation in a closed loop system. During the operations, water moves through the inlet section into the contract section of the venturi, which increases the rate of water flow and reduces the pressure as per the Bernoulli’s theorem. In order to study the oxygen transfer coefficient at varying discharge, the system worked by a single hole and accordingly applied to the larger number of holes for both the throat lengths of venturi. It was observed that the oxygen transfer coefficient proportionally linked to the DO diffusion with increasing rate of discharge. The oxygen transfer coefficient found to be increased by 31% and 55% at 40 and 80 mm throat length respectively, with increasing the discharge. The rate of DO diffusion found higher causes more surface area of contact between air and water through maximum air entrainment. Moreover aeration efficiency also increases with the rate of increasing discharge for the maximum size of throat length. The maximum SOTR values was obtained 0.0035, 0.0041, and 0.0050 kgO2/h at varying discharge of 0.50, 0.58 and 0.67 l/s respectively for 40 mm throat length. For the 80 mm throat length, the SOTR values varies from 0.0042, 0.0062 and 0.0091 kgO2/h at increasing discharge of 0.50, 0.58 and 0.67 l/s respectively with increasing number of holes.
Adopting zero accident vision in India: a conceptual framework
Authors: Narain Jai , Meena Makkhan Lal , Dangayach Govind Sharan , Patnaik Amar
Published: January 2021

The research concentrates on the five success factors of Zero Accident Vision (ZAV) methodologies, which are the pillar of ZAV. As safety is the priority of any industry, so, the research aims to contribute a new idea for accident prevention in high-risk industries. The research is based on the survey format in which the rating of workers are taken on important factors regarding accident prevention and awareness, and from the basis of that result, we find the necessary critical factors. From the result, it can be concluded that what are the factors which are necessary for the implementation of ZAV. As earlier there is limited work that has been done in the field of ZAV, so here a framework is proposed for ZAV to prevent the accident that will lead the industries towards zero accident vision.
Sustainable Construction Using EPS Beads in Light Weight Blocks to form Innovative Foam Concrete as a Green Building Material
Authors: Moon A S , Patel Dr. A
Published: January 2021

We assume to build up another sort of basic light weight concrete by supplanting the coarse total with EPS dabs. Extended Polystyrene (EPS) this is light in weight and it has been utilized as in building applications. EPS is in granular structure and it is utilized in light weight cement to make the solid lighter from 950 kg/m³ to 1350kg/m³. In this paper we did test examination on the designing properties, as compressive quality, modulus of flexibility, drying shrinkage and creep, of polystyrene total cement fluctuating in density. Factors, for instance, water/solid extent, polystyrene/solid extent, solid substance, advancement, compaction, fire, resistance. At the completion of the examination, a philosophy for arranging EPS light weight solid mixes is plot.
Role of micro-factors on microstructure and on the tribological performance of HVOF coatings: A review
Authors: Vats Alok , Patnaik Amar , Meena M L , Shringi Dinesh
Published: January 2021

Mechanical components, whether stationary or moving are subjected to wear and corrosion. A combined effect of these two is even more deleterious. Thermal spray technique proves to be an effective solution to address these issues. HVOF coatings owing to their inherent characteristics like high hardness, adhesion, density (porosity <1%) its provide enhanced mechanical and tribological performance and so are widely used across industries. Micro-factors like presence of pores, oxides and cracks, matrix and binder properties, addition of Cr, cohesive strength and boundary regions etc. do influence the coating behaviour, besides the deposition parameters. The objective of this paper is to review the effect of above mentioned factors on the wear and corrosive performance of the coatings for industrial and research viewpoint.
Optimization of Abrasive Wear Behaviour of Cenosphere Filled Basalt-Epoxy Composites Using Taguchi Approach
Authors: sharma Vikas , Meena M L , Chaudhary A K , Kumar Sundeep
Published: January 2021

The current research work investigates the three-body abrasive wear analysis of cenosphere particulate filled chopped basalt fiber (40 wt.% constant) reinforced epoxy composites for developing light weight, low cost, and sustainable composite. The effect of cenosphere particulate on the composite was investigated. The composite laminates are fabricated by traditional open mold casting technique. The cenosphere particulate is mixed (0-15 wt.%, step of 5 wt.%) in the composites. Abrasive wear process input parameters like: filler loading, normal load, sliding distance, and abrasive size are optimize by using Taguchi design of experiments. From the results, it is clearly seen that 10 wt.% cenosphere filled basalt-epoxy composite (EBC 10) shows lowest abrasive wear rate in a steady state abrasive wear condition (with a variation in sliding distance and normal load). Taguchi experimental design technique is an effective optimization technique and gives a better outcome.
Review: Technological Development of Heat Transfer Enhancement in Two Phase Flow by using Passive Method
Authors: Jadhav Gajanan Z. , Gupta K K
Published: January 2021

The Heating, Ventilation, Air conditioning & Refrigeration application always shows an opportunity to enhance the heat transfer rate. With these motives, researchers explored the use of passive methods in single phase flow which exhibits promising results of heat transfer enhancement. On the other hand, researchers investigated the effect of the passive method in Two phase flow, which also shows promising results in heat transfer enhancement. Two phase flow includes Boiling, Evaporation & condensation phenomenon. This paper focused on the review of the experimental studies conducted on the use of heat transfer enhancement in the condensation process mostly. Out of this passive method, Micro fin tube shows better heat transfer enhancement and less pressure drop compared to other methods. It has been observed that the use of porous media also showing promising effects in heat transfer enhancement and it’s fetching the attention of researchers. Therefore, this review work also reviewed the numerical studies on the use of porous media in two phase flow. It is needed to explore the different structure and optimum design of porous media, which have high heat transfer enhancement with low pressure drop penalty. Also, the use of low Global Warming Potential refrigerant effects needs to be explored, which could be a better alternative for existing refrigerants.