bluuebunny/crossref_metadata_2025_split huggingface dataset:
Power factor measuring device using microcontroller for single-phase consumers
Authors: Diniş C M , Popa G N , Iagăr A 
Published: February 2021

Abstract
The paper presents a device with microcontroller for measuring the power factor used for single-phase low voltage electrical consumers. Voltage and current are measured, and the paper presents two constructive variants of pulse circuits (TTL compatible) used to measure the phase-shift between current and voltage. In the first constructive variant, without galvanic separation, the voltage measurement is performed with a voltage divider connected in parallel with the consumer, and the current measurement is made by a shunt resistor connected in series with the consumer. In the second construction variant, with galvanic separation, the voltage is measured by a step-down voltage transformer, and the current is measured with a current transformer that has a load resistance. The signals coming from the voltage and current measuring equipment are limited by a group of diodes, then amplified-separated, and the resulting signals are connected to the input of a XOR TTL logic gate. The signal from the XOR TTL gate output has constant amplitude pulses and time durations proportional to the phase-shift value between current and voltage. The signal after the XOR TTL gate is applied to the digital input of a microcontroller development board that, also, has an LCD shield. The program used to calculate the power factor according to the pulse length (proportional with phase-shift value) is presented. Experiments are performed with RL consumers to measure the power factor and the obtained measurements are compared with those measured with a precision device (power quality analyser).
The importance of recovering precious metals from waste electrical and electronic equipment
Authors: Ardelean M , Ardelean E , Mihuţ G , Găianu O 
Published: February 2021

Abstract
The evolution of electronic equipment in recent decades is experiencing a remarkable development. Due to increasing of consumption and also a very fast replacement rate due mainly to obsolescence, the amount of resulting electrical and electronic waste (WEEE) is increasing.
The WEEE term includes all of electrical and electronic equipment starting from mobile phones, computers, video cameras to tv set, washing machines, refrigerators. In other words, all electrical and electronic equipment from a household, electronic equipment from automotive or industrial electronic components. Now in all worldwide it is estimated that WEEE represents about 5% of all municipal solid waste.
The recovery process can be taken into account only if the cost of recovery is much lower than the value of the precious metals recovered from this. Regarding to waste disposal restrictions and strict environmental regulations, are needed economically viable and environmentally friendly technologies.
The paper presents the results of laboratory experiments on the recovery of precious metals, especially gold, present in various electrical and electronic components. WEEE used in the experiments was used from mobile phones, computer motherboards, computerized microprocessors and various types of gold-plated contacts.
Possibilities of 3D reconstruction of the vehicle collision scene in the photogrammetric environment Agisoft Metashape 1.6.2
Authors: Dascăl A , Popa M 
Published: February 2021

Abstract
Agisoft Metashape software is an advanced 3D modelling solution for a road accident scene. The re-creation of the accident scene through high quality professional content, allows the use of the result obtained by this photogrammetric method in the subsequent reconstruction of the dynamics of any road accident, having the advantage that the accident scene can be made and presented suggestively in 3D from different positions.
Half-hard cast-iron rolls: statistically research on the manufacturing technology for increase their quality and safety in exploitation
Authors: Kiss I , Alexa V , Cioată V G , Ratiu S 
Published: February 2021

Abstract
The regression analysis provides an opportunity to specify hypotheses concerning the quality assurance of cast-iron rolls, as well as explanatory factors in their manufacturing practice. When the analysis is correctly executed, having on base the statistically valid adjustment, this can produce quantitative effects on the quality assurance process. In the practice of the rolling rolls manufacturing by casting many variables interact with each other simultaneously (the iron properties, the casting equipment and they execution, the casting temperature, the cooling and solidification and so on). Multivariate research and visualization comes to the fore when the engineers have difficulties in comprehending many dimensions at one time, especially in the iron melting and alloying stages. In order to establish the optimal condition for hardness assurance in the cast-iron rolls manufacturing we proposed a statistical modelling study by using the multivariate regression. Our research propose to analyse the half-hard cast-iron rolls, an analysis defined by the statistically analyse of the cast rolls manufacturing technology, using the modelling phenomenon and the mathematical approach. The optimization model is based on industrial data, obtained from half-hard cast-iron rolls. Their analysis shall lead to the optimization pattern, through the prism of the multicomponent correlations, expressed by mathematical formulae.
Using SHERPA screening tool for design and assessment of local and regional air quality management
Authors: Popescu F , Vujic B , Cioabla A E , Marceta U , Dungan L I , Trif-Tordai G , Laza E A 
Published: February 2021

Abstract
As atmospheric pollution continue to be a significant issue on global level, but with a particular importance at European Union level, the air pollution reduction policies will continue to be enforced in the next decades. At EU level, especially on most developed countries, NO2 and Particulate Matter (fine and coarse fractions) remain an acute problem. To help decision factors to have a better view on entire EU region the SHERPA (Screening for High Emission Reduction Potentials on Air quality) was developed, a tool that was proven helpful in addressing source allocation, governance and the assessment of scenario impacts.
Manufacturing process management for cast iron brake blocks
Authors: Bucur F , Josan A , Socalici A , Gaianu O 
Published: February 2021

Abstract
In order to insure a proper management in cast iron foundries it is necessary to coordinate all the processes that are involved in manufacturing cast parts. The organisation management offers the necessary conditions for developing activities, with great emphasis on the activity of quality control. The paper presents the necessity of establishing a management strategy which can lead to the supervision of the entire manufacturing cycle of cast iron brake blocks for rolling stock. To this end, it is necessary to measure, monitor and analyze the results obtained in the industrial practice and to compare them with product standards.
Research on the influence of casting powders on the higher quality of continuous cast semi-finished parts
Authors: Radu M , Heput T , Ardelean E , Dascal A 
Published: February 2021

Abstract
Pursuant of the modernization of steel elaboration and casting technologies, at present over 90% of the liquid steel undergoes continuous casting. The quality of the cast parts is influenced by: the casting temperature and rate, the flow rate of the cooling water and the characteristics of the casting powders. The research under consideration was done on a low manganese alloy steel X60QS elaborated in an EBT-type, 100 ton oven and cast on a 5-strand MCT casting machine. The paper gives the results of the research on the variation of the carbon, manganese and sulphur content per cast product for each casting strand and for each rod of the strand. The research managed to establish the causes that lead to deviations from the required chemical content for these elements, as well as the possibilities of eradicating them. The results are applicable in research and in practice.
Technology of thin metal sheet cutting with fiber laser
Authors: Zgripcea L , Putan V , Ardelean M , Birtok Baneasa C 
Published: February 2021

Abstract
Laser cutting is a thermal cutting process where it is made use of the physical fact that laser light is absorbed in materials. The process is used for many materials in the manufacturing industry. Nowadays, the most suitable laser regarding range of materials, cutting speed, cutting quality is fiber laser. The article studies the correlation between cut quality and process parameters for thin plates, steel and aluminum. The laser machine used for experiments is a Continuous Wawe fiber laser with 1000W power source.
Structural analysis of a modulated load-bearing structure designed to investigate the interaction between soil and the working parts of agricultural machines
Authors: Cardei P , Constantin N , Sfiru R , Muraru V , Muraru S L 
Published: February 2021

Abstract
The article presents how to approach the structural analysis of a modulated load-bearing structure (MLBS) for researching the interaction between the soil and the working parts of agricultural machines. The special approach, in relation to the usual structures, is due to the fact that the supporting structure is a modulated, multifunctional one and, consequently, all the usual modular types of operation must be tested. The structure is analyzed in the hypothesis of the loads that maintain the demands of the materials used in the characteristic range of the linear elasticity, because the structure is expected to work in such conditions. The analyzed modulated structure is obtained by modular design for use in research, in several working variants. The authors also present the difficulties related to the transformations of CAD / CAM models into CAD / CAE models and opinions on the necessity of mixed analysis teams in addressing such problems.
Biogas production on lab-scale: utilization of wastewater from Hunedoara treatment plant
Authors: Ivanovici M , Cioabla A E , Lelea D , Popescu F , Dunga L I , Ordodi L V 
Published: February 2021

Abstract
In the present work, the potential of wastewater procured from a local treatment plant situated in Hunedoara in order to produce biogas was assessed in anaerobic co-digestion process. Finding appropriate combinations of feedstocks involved in the process represents a key factor in obtaining high biogas amounts and also high quality of biogas. Therefore, a case study was carried out in a lab-scale installation for biogas production using a suspension consisting of wastewater, animal (cow and chicken) slurry and degraded corn. The wastewater and animal slurry were selected as the main feedstock, providing for the microbial community required in the anaerobic digestion, in a volume ratio of 3:1 animal slurry to wastewater. Moreover, the feedstocks were subjected to several characterization methods: determination of total content of carbon, hydrogen and nitrogen and the content of volatile matter using European Standards. The process was performed in thermophilic conditions and controlled mixing of the suspension for a period of 24 days. The performances were appreciated by monitoring the amount of the produced biogas and the main gaseous components of the biogas: CH4, CO2 and H2S.
Improving multi-material structures using topological optimization and the modified SIMP method
Authors: Zhigalov M V , Bodyagina K S , Krysko V A 
Published: February 2021

Abstract
This paper proposes to use a modified SIMP method to solve the problem of topological optimization of structures containing components of more than two different materials, which must be distributed in such a way as to obtain the best structural characteristics using one continuous design variable. The paper demonstrates the effectiveness of the proposed method by the example of solving the problem of topological optimization of a structure made of multimaterial. With the help of such a solution, it is possible to obtain reliable structures with improved mechanical characteristics, which can be used to solve real problems of design and manufacture of complex structures.
Econometric modeling of economic factors’s impact on the labor force per capita
Authors: Liskina E Ju , Davydova E I 
Published: February 2021

Abstract
In this article, we study the impact of a number of economic factors on the number of workers per capita. We use the panel data analysis method. We found that the best model is the one with fixed effects. We have identified the factors that have the most significant impact on the explanatory variable. The number of vacancies per capita, the capacity of outpatient clinics and the number of university students per capita have a positive statistically significant effect on the labor force per capita. The capital-labor ratio, the population per doctor and the total living space per inhabitant on average have a negative statistical effect on the labor force per capita. The values of individual effects of the regions were positive.
The scenario modeling of regional competitiveness risks based on the Chapman-Kolmogorov equations
Authors: Veshneva I , Chernyshova G 
Published: February 2021

Abstract
The paper is devoted to the development of analytical tools for assessing the dynamics of risks to the competitiveness of Russian regions within the conditions of incomplete information. The choice of analysis methods for assessing the risk dynamics was substantiated. A solution based on the implementation of homogeneous Markov models with a discrete set of states and continuous time was proposed, it allowed to assess the probability of risks affecting regional competitiveness. A hierarchical structure of factors that determine the risks of regional competitiveness was formed as a cause-and-effect graph. Corresponding systems of Kolmogorov – Chapman differential equations were obtained and solved. An example for analyzing a 3-element minimal cut set of a cause-effect graph was presented. A set of scenarios for the study of risks and their combinations in various conditions was proposed. The solution was obtained for three leading Russian regions. For a set of scenarios, numerical assessments of risk factors that significantly affect the decline in the competitiveness of regions have been fulfilled. The study results made it possible to rank the effects of critical event occurrence, to identify the most significant risk factors for the loss of sustainable development and competitiveness for the Russian Federation regions.
Parameter tuning of a genetic algorithm for finding central vertices in graphs
Authors: Vlasov A , Khomchenko A , Faizliev A , Mironov S , Grigoriev A 
Published: February 2021

AbstractThis paper studies a genetic algorithm for finding the central vertices in graphs. The algorithm uses a different approach to the solution method presentation and describes a new insight in the crossover process. Studies are conducted to find the optimal parameters of the genetic algorithm such us crossover probability, mutation probability and population size. Based on the results, it can be claimed that with the right parameters, our algorithm shows good running time results with high accuracy of the correct answers.
XXXV International Conference on Equations of State for Matter
Authors: Fortov V E , Khishchenko K V , Karamurzov B S , Sultanov V G , Kadatskiy M A 
Published: February 2021

Abstract
This paper is a preface to the proceedings of the XXXV International Conference on Equations of State for Matter, which was held at the Cheget pension in the village of Terskol, in the settlement of Elbrus, in the Kabardino-Balkar Republic of the Russian Federation, from March 1 to 6, 2020.
Equation of state for vanadium at high pressures
Authors: Khishchenko K V 
Published: February 2021

Abstract
An equation of state for vanadium is proposed over a wide range of densities and pressures in the form of an analytic function of pressure on the specific volume and internal energy. The calculated cold curve and shock adiabat are compared with the available data from static and dynamic compression experiments. The developed equation of state can be used to simulate physical processes in vanadium under conditions of high energy density.
Lanthanum group: Detection and correction of errors in orbital binding energy measurements of internal shells
Authors: Shpatakovskaya G V 
Published: February 2021

Abstract
Experimental data on electronic binding energies in a ground state of lanthanides are analyzed. Internal individual shells K, L, M, N are studied in detail. The data scatter is discussed. Atomic number similarity law of orbital binding energies is shown and deviations from it in some experimental results are treated as measurement errors. Polynomial interpolation of patterns makes it possible to restore missing and correct erroneous data. Comparison is made with experimental data from other sources and theoretical results.
Method of verification of performance of composite package for protection of thin-walled constructions against non-stationary one-sided loadings
Authors: Ostrik A V , Nikolaev D N 
Published: February 2021

Abstract
Computing-experimental method of verification of operability of composite porous package for protection of thin-walled constructions from non-stationary one-sided loadings is proposed. A set of explosive devices for generate loads of the required space-time distributions is described. Two new explosive devices for generation of low-pulse loads of microsecond duration with low difference in loading time at the surface of the tested composite constructions are considered. Time deformation profiles of glass-plastic cylindrical shell under low-impulse load of microsecond duration are given. It is received that use of wire or foil sensors for measurement of deformations give close results when the shell stage of deformation of glass-plastic thin-walled constructions is investigated.
Electrical resistivity of zirconium carbide at 1200–2500 K
Authors: Kostanovskiy A V , Kostanovskaya M E , Zeodinov M G , Pronkin A A 
Published: February 2021

Abstract
Zirconium carbide ZrC produced from nano-sized powders is a new material; its properties have not, in fact, been studied. We present the experimental results on the electrical resistivity of the zirconium carbide within the temperature range of 1200–2500 K. The ZrC specimens were prepared by spark plasma sintering from nano-size particles at a temperature of 2100 K. The goal of the present work is to compare the obtained results of the electrical resistivity with data for ZrC produced by traditional methods.
Periodic error while processing data from a velocity interferometer system for any reflector
Authors: Kazieva T V , Gubskiy K L , Kuznetsov A P , Pirog V A , Tishchenko I Yu 
Published: February 2021

Abstract
When processing experimental data with systems such as velocity interferometer system for any reflector (VISAR), periodic measurement uncertainty arises. The appearance of its uncertainty is investigated and computer modeling of signal processing with random noise is carried out. Analytical dependences of the error value on the signal-to-noise ratio and signal phase are obtained. Methods of reducing this error are considered.
Effect of mechanical activation on combustion characteristics of Al–CuO powder mixture
Authors: Ananev S Yu , Grishin L I , Yankovsky B D , Kirilenko V G , Dolgoborodov A Yu 
Published: February 2021

Abstract
This paper presents the results of experiments carried out to reveal the influence of the initial parameters of the thermite mixture Al–CuO on the signs of a chemical reaction between its components. Initial parameters were the characteristics of the starting components, preparation conditions and characteristics of the mixture and samples, experimental schemes, methods of initiation. The most important parameter was the preliminary mechanical activation of mixture. The prepared mixture with controlled porosity was placed in experimental assemblies and a chemical reaction was initiated. Values and tendencies of the brightness temperature and the propagation rate of reaction area were determined for different initial parameters of mixture and initiation conditions. The reaction in the volume of the experimental assembly goes into flare combustion in open space. Values of brightness temperature at the stage of flare formation have a stochastic character, determined by the random distribution of reaction sites in the initial volume of the components. A high-speed camera, a pyrometer, photoelectronic and electrocontact sensors were used as diagnostic tools. The final goal of the study is to optimize parameters of mechanical activation of mixture for its effective applying in various conditions.
Study of combustion wave propagation in linear charges from mechanically activated thermite mixtures
Authors: Yankovsky B D , Dolgoborodov A Yu , Grishin L I , Ananev S Yu 
Published: February 2021

Abstract
The combustion wave propagation in Al–CuO and Al–Bi2O3 termite mixtures was experimentally investigated. Waveforms of electric current through the reaction area between electrodes with a given potential difference, chronograms of piezo- and photodiode response, the data of pyrometric measurements, as well as photos of the glowing area were obtained and analyzed. There were revealed the advance filtration of the gas component through pores of mixture, the generation of charges providing considerable electrical conductivity of chemical reaction products, the connection of electrical conductivity dynamics with the optical radiation of the chemical conversion region.
Buoyant flames in near the lower flammability limit hydrogen–air mixtures
Authors: Gavrikov A I , Golub V V , Volodin V V , Mikushkin A Yu , Danilin A V 
Published: February 2021

Abstract
The paper presents the results of large-scale experimental and simulation study of the propagation of premixed near the lower flammability limit hydrogen–air spherical flame. Experiments were carried out in a cylindrical volume of 4.5 m3 covered with thin polyethylene film. The effect of buoyancy and stability of the flame ball in the unconfined volume are studied experimentally and numerically. Numerical analysis of the problem shows that the flame ball becomes unstable after some period of stable propagation that qualitatively corresponds with experimental results. The effect of chemistry in a flame ball propagation process is studied numerically. A comparison of experimental results and numerical simulations are presented. A comparison of numerical simulations with and without chemistry is shown. The subject and results of the study are of critical importance for the industrial explosion safety and hydrogen safety of nuclear power plants.