bluuebunny/crossref_metadata_2025 huggingface dataset:
Faint polarised sources in the Lockman Hole field at 1.4 GHz
Authors: Berger A. , Adebahr B. , Herrera Ruiz N. , Wright A. H. , Prandoni I. , Dettmar R.-J.
Published: July 2021

Context. In the context of structure formation and galaxy evolution, the contribution of magnetic fields is not well understood. Feedback processes originating from active galactic nucleus (AGN) activity and star formation can be actively influenced by magnetic fields, depending on their strength and morphology. One of the best tracers of magnetic fields is polarised radio emission. Tracing this emission over a broad redshift range therefore allows an investigation of these fields and their evolution.

Aims. We aim to study the nature of the faint, polarised radio source population whose source composition and redshift dependence contain information about the strength, morphology, and evolution of magnetic fields over cosmic timescales.

Methods. We use a 15-pointing radio continuum L-band mosaic of the Lockman Hole, observed in full polarisation, generated from archival data of the Westerbork Synthesis Radio Telescope. The data were analysed using the rotation measure synthesis technique. We achieved a noise of 7 μJy beam−1 in polarised intensity, with a resolution of 15″. Using infrared and optical images and source catalogues, we were able to cross-identify and determine redshifts for one-third of our detected polarised sources.

Results. We detected 150 polarised sources, most of which are weakly polarised with a mean fractional polarisation of 5.4%. No source was found with a fractional polarisation higher than 21%. With a total area of 6.5 deg2 and a detection threshold of 6.25σ, we find 23 polarised sources per deg2. Based on our multi-wavelength analysis, we find that our sample consists of AGN only. We find a discrepancy between archival number counts and those present in our data, which we attribute to sample variance (i.e. large-scale structures). Considering the absolute radio luminosity, we find a general trend of increased probability of detecting weak sources at low redshift and strong sources at high redshift. We attribute this trend to a selection bias. Further, we find an anti-correlation between fractional polarisation and redshift for our strong-source sample at z ≥ 0.6.

Conclusions. A decrease in the fractional polarisation of strong sources with increasing redshift cannot be explained by a constant magnetic field and electron density over cosmic scales; however, the changing properties of cluster environments over cosmic time may play an important role. Disentangling these two effects requires deeper and wider polarisation observations as well as better models of the morphology and strength of cosmic magnetic fields.
Multi-epoch properties of the warm absorber in the Seyfert 1 galaxy NGC 985
Authors: Ebrero J. , Domček V. , Kriss G. A. , Kaastra J. S.
Published: July 2021

Context. NGC 985 was observed by XMM-Newton twice in 2015, revealing that the source was coming out from a soft X-ray obscuration event that took place in 2013. These kinds of events are possibly recurrent since a previous XMM-Newton archival observation in 2003 also showed signatures of partial obscuration.

Aims. We have analyzed the high-resolution X-ray spectra of NGC 985 obtained by the Reflection Grating Spectrometer onboard XMM-Newton in 2003, 2013, and 2015 in order to characterize the ionized absorbers superimposed to the continuum and to study their response as the ionizing flux varies.

Methods. The spectra were analyzed with the SPEX fitting package and the photoionization code CLOUDY.

Results. We found that up to four warm absorber (WA) components were present in the grating spectra of NGC 985, plus a mildy ionized (logξ ∼ 0.2−0.5) obscuring (NH ∼ 2 × 1022 cm−2) wind outflowing at ∼ − 6000 km s−1. The absorbers have a column density that ranges from ∼1021 to a few times 1022 cm−2, and ionization parameters ranging from logξ ∼ 1.6 to ∼2.9. The most ionized component is also the fastest, moving away at ∼ − 5100 km s−1, while the others outflow in two kinematic regimes, ∼ − 600 and ∼ − 350 km s−1. These components showed variability at different time scales in response to changes in the ionizing continuum. Assuming that these changes are due to photoionization and recombination mechanisms, we have obtained upper and lower limits on the density of the gas. We used these limits to pinpoint the location of the warm absorbers, finding that the closest two components are at parsec-scale distances, while the rest may extend up to tens of parsecs from the central source. With these constraints on the density and location, we found that the fastest, most ionized WA component accounts for the bulk of the kinetic luminosity injected back into the interstellar medium of the host galaxy, which is on the order of 0.8% of the bolometric luminosity of NGC 985. According to the models, this amount of kinetic energy per unit time would be sufficient to account for cosmic feedback.

Conclusions. Observations of the onset and conclusion of transient obscuring events in active galactic nuclei are a key tool to understand both the dynamics and physics of the gas in their innermost regions, and also to study the response of the surrounding gas as the ionizing continuum varies.
X-ray analysis of thePlanck-detected triplet-cluster system PLCK G334.8-38
Authors: Kolodzig Alexander , Aghanim Nabila , Douspis Marian , Pointecouteau Etienne , Lecoq Edouard
Published: July 2021

We conducted an X-ray analysis of one of the twoPlanck-detected triplet-cluster systems,PLCK G334.8-38.0, with a ∼100 ks deepXMM-Newtondata. We find that the system has a redshift ofz = 0.37 ± 0.01 but the precision of the X-ray spectroscopy for two members is too low to rule out a projected triplet system, demanding optical spectroscopy for further investigation. In projection, the system looks almost like an equilateral triangle with an edge length of ∼2.0 Mpc, but masses are very unevenly distributed (M500 ∼ [2.5, 0.7, 0.3]×1014 M⊙from bright to faint). The brightest member appears to be a relaxed cool-core cluster and is more than twice as massive as both other members combined. The second brightest member appears to be a disturbed non-cool-core cluster and the third member was too faint to make any classification. None of the clusters have an overlappingR500region and no signs of cluster interaction were found; however, theXMM-Newtondata alone are probably not sensitive enough to detect such signs, and a joint analysis of X-ray and the thermal Sunyaev-Zeldovich effect is needed for further investigation, which may also reveal the presence of the warm-hot intergalactic medium within the system. The comparison with the otherPlanck-detected triplet-cluster-system (PLCK G214.6+36.9) shows that they have rather different configurations, suggesting rather different merger scenarios, under the assumption that they are both not simply projected triplet systems.
DEATHSTAR: nearby AGB stars with the Atacama Compact Array
Authors: Andriantsaralaza M. , Ramstedt S. , Vlemmings W. H. T. , Danilovich T. , De Beck E. , Groenewegen M. A. T. , Höfner S. , Kerschbaum F. , Khouri T. , Lindqvist M. , Maercker M. , Olofsson H. , Quintana-Lacaci G. , Saberi M. , Sahai R. , Zijlstra A.
Published: July 2021

Aims. We aim to constrain the sizes of, and investigate deviations from spherical symmetry in, the CO circumstellar envelopes (CSEs) of 16 S-type stars, along with an additional 7 and 4 CSEs of C-type and M-type AGB stars, respectively.

Methods. We map the emission from the CO J = 2–1 and 3–2 lines observed with the Atacama Compact Array (ACA) and its total power (TP) antennas, and fit with a Gaussian distribution in the uv- and image planes for ACA-only and TP observations, respectively. The major axis of the fitted Gaussian for the CO(2–1) line data gives a first estimate of the size of the CO-line-emitting CSE. We investigate possible signs of deviation from spherical symmetry by analysing the line profiles and the minor-to-major axis ratio obtained from visibility fitting, and by investigating the deconvolved images.

Results. The sizes of the CO-line-emitting CSEs of low-mass-loss-rate (low-MLR) S-type stars fall between the sizes of the CSEs of C-stars, which are larger, and those of M-stars, which are smaller, as expected because of the differences in their respective CO abundances and the dependence of the photodissociation rate on this quantity. The sizes of the low-MLR S-type stars show no dependence on circumstellar density, as measured by the ratio of the MLR to terminal outflow velocity, irrespective of variability type. The density dependence steepens for S-stars with higher MLRs. While the CO(2–1) brightness distribution size of the low-density S-stars is in general smaller than the predicted photodissociation radius (assuming the standard interstellar radiation field), the measured size of a few of the high-density sources is of the same order as the expected photodissociation radius. Furthermore, our results show that the CO CSEs of most of the S-stars in our sample are consistent with a spherically symmetric and smooth outflow. For some of the sources, clear and prominent asymmetric features are observed which are indicative of intrinsic circumstellar anisotropy.

Conclusions. As the majority of the S-type CSEs of the stars in our sample are consistent with a spherical geometry, the CO envelope sizes obtained in this paper will be used to constrain detailed radiative transfer modelling to directly determine more accurate MLR estimates for the stars in our sample. For several of our sources that present signs of deviation from spherical symmetry, further high-resolution observations would be necessary to investigate the nature of, and the physical processes behind, these asymmetrical structures. This will provide further insight into the mass-loss process and its related chemistry in S-type AGB stars.
Populating the brown dwarf and stellar boundary: Five stars with transiting companions near the hydrogen-burning mass limit
Authors: Grieves Nolan , Bouchy François , Lendl Monika , Carmichael Theron , Mireles Ismael , Shporer Avi , McLeod Kim K. , Collins Karen A. , Brahm Rafael , Stassun Keivan G. , Gill Sam , Bouma Luke G. , Guillot Tristan , Cointepas Marion , Dos Santos Leonardo A. , Casewell Sarah L. , Jenkins Jon M. , Henning Thomas , Nielsen Louise D. , Psaridi Angelica , Udry Stéphane , Ségransan Damien , Eastman Jason D. , Zhou George , Abe Lyu , Agabi Abelkrim , Bakos Gaspar , Charbonneau David , Collins Kevin I. , Colon Knicole D. , Crouzet Nicolas , Dransfield Georgina , Evans Phil , Goeke Robert F. , Hart Rhodes , Irwin Jonathan M. , Jensen Eric L. N. , Jordán Andrés , Kielkopf John F. , Latham David W. , Marie-Sainte Wenceslas , Mékarnia Djamel , Nelson Peter , Quinn Samuel N. , Radford Don J. , Rodriguez David R. , Rowden Pamela , Schmider François–Xavier , Schwarz Richard P. , Smith Jeffrey C. , Stockdale Chris , Suarez Olga , Tan Thiam-Guan , Triaud Amaury H. M. J. , Waalkes William , Wingham Geof
Published: July 2021

We report the discovery of five transiting companions near the hydrogen-burning mass limit in close orbits around main sequence stars originally identified by the Transiting Exoplanet Survey Satellite (TESS) as TESS objects of interest (TOIs): TOI-148, TOI-587, TOI-681, TOI-746, and TOI-1213. Using TESS and ground-based photometry as well as radial velocities from the CORALIE, CHIRON, TRES, and FEROS spectrographs, we found the companions have orbital periods between 4.8 and 27.2 days, masses between 77 and 98 MJup , and radii between 0.81 and 1.66 RJup . These targets have masses near the uncertain lower limit of hydrogen core fusion (~73-96 MJup ), which separates brown dwarfs and low-mass stars. We constrained young ages for TOI-587 (0.2 ± 0.1 Gyr) and TOI-681 (0.17 ± 0.03 Gyr) and found them to have relatively larger radii compared to other transiting companions of a similar mass. Conversely we estimated older ages for TOI-148 and TOI-746 and found them to have relatively smaller companion radii. With an effective temperature of 9800 ± 200 K, TOI-587 is the hottest known main-sequence star to host a transiting brown dwarf or very low-mass star. We found evidence of spin-orbit synchronization for TOI-148 and TOI-746 as well as tidal circularization for TOI-148. These companions add to the population of brown dwarfs and very low-mass stars with well measured parameters ideal to test formation models of these rare objects, the origin of the brown dwarf desert, and the distinction between brown dwarfs and hydrogen-burning main sequence stars.
Classification of diagnostic features of transient signals in the electric power industry
Authors: Khuziashev Rustem , Kuzmin Igor , Irkagalieva Iluza
Published: July 2021

Problems of practical implementation of traveling wave fault location caused by the registration of signals of different nature are considered. Analysis of the experimentally recorded traveling waves made it possible to divide them into 4 groups caused by partial discharges, lightning overvoltages, scheduled switching and fault commutations. The network dispatchers only needs the fault commutation information. Traveling waves recorded near the place of their origin have different meanings of diagnostic signs. The magnitude of the pre-alarm noise, the number of pulses in the signal and the duration of the signal are used as diagnostic indicators. These three diagnostic signs allow one to recognize each of the 4 causes of the travelling waves.
Chemical Activity and Morphology of Nanostructured Plasma-Sprayed Titanium Induced by Nitrogen and Argon Ions
Authors: Perinskaya Irina , Perinsky Vladimir , Kalganova Svetlana
Published: July 2021

The paper focuses on the chemical characteristics of ion-beam passivation effects (of the first-third order) of titanium depending on the dose of implanted ions. The key objective is electron microscopy and SPM-based analysis of nanostructured VT1-00 titanium surfaces produced by entering nitrogen and argon ions of high energy. This type of surfaces can find application in fabrication of devices for the power engineering industry. The obtained experimental data provide evidence of a carbon nanocoating over the surface of titanium implanted with accelerated nitrogen ions, which is similar to that acquired upon titanium implantation with argon ions. A hypothesis is formulated about the existence of a mechanism for changing the chemical activity of titanium as a result of ion-beam nanostructuring – ion-stimulated synthesis of.
Determination of state of electrical equipment by spectra of wattmetrograms
Authors: Manakhov Valeriy , Tsvetkov Alexey
Published: July 2021

The purpose of the work is to develop a method of diagnostics and control of oil production equipment to improve energy efficiency and optimize operation modes, through the use of a wattmeter program and its spectrum. The method of diagnostics according to the wattmetrogram is based on obtaining the active power spent by the electric motor for one period of rocking of the rocker. Analysis of the spectrum of wattmetrograms makes it possible to more accurately diagnose defects of this equipment. Thus, control over the spectra of the wattmetrogram is a more accurate and promising method of diagnosing equipment. Materials and methods: In the development of this issue, both domestic and foreign literature was used. The technical data of the control stations and sensors were used on the basis of actual electrical equipment. The prospects and benefits of using diagnostic options weltmetropole: relatively small number of sensors (current and voltage transformers); ability to measure the electric power consumed by the drive; ability to integrate with automated systems of technical and commercial electricity metering; the task is relevant already today, but it is quite promising in the future, due to the rapid development of technologies that allow for digital processing of wattmetrograms; use of these technologies in practice; economic advantages over similar representatives of this segment; service life of more than 20 years; ability to work in a wide temperature range -40 — +60.
“Chemical Triangle” as a modern intellectual basis for digital systematization of energy characteristics of substances
Authors: Sirotkin Oleg , Sirotkin Rostislav
Published: July 2021

It was shown that sustainable power and mechanical engineering relies primarily on chemical transformation of matter, since a chemical substance (in the form of homo- and heteronuclear compounds of elements) is the most accessible type of substance on Earth. As a result, low-, oligo- and high-molecular and non-molecular (metallic and ionic) chemicals and products (fuels, polymers, alloys, glasses, etc.) are primary raw materials for production of thermal and electrical energy, as well as materials needed for alternative energy production. It was noted that the main drawback of the modern expert system for assessing the energy properties of substances used as fuels is not taking into account the influence of the chemical bond type on its energy and energy characteristics of fuels in general. It was shown that the solution to this problem is possible through the use of the unified model of chemical bond of elements, which considers any chemical bond as an overlay (resonance) of a 100% covalent bond with either metal or metal and ionic components, with a subsequent assessment of the effect of each of them on total energy of the mixed bond. This model is the fundamental basis of the System of chemical bonds and compounds (SCBC) in the form of the “Chemical Triangle”. The possibility of using the “Chemical Triangle” as a modern intellectual basis for digital systematization and creation of a database of energy characteristics of various substances based on homo- and heteronuclear compounds of elements was shown. A computer database was developed to assess the complex impact of composition and chemical bond type on its energy characteristics, structure and properties of substances and materials.
Pulse-width modulation in the autonomous voltage inverter in identifying parameters of the three-phase asynchronous motor
Authors: Makarov Valery , Zagirova Veronika , Vagapov Georgii
Published: July 2021

This paper deals with control algorithm of a two-level autonomous voltage inverter with pulsewidth modulation in forming test phase voltages for identification of parameters of a three-phase asynchronous motor. Necessary conversion is carried out, the laws of change of phase voltages of an autonomous inverter are obtained. The feasibility of using third order active Butterworth filters for determining first harmonics of phase voltages is shown. By means of computer simulation and experimental research, it is revealed that the required shapes of phase voltages can be implemented in a twolevel autonomous voltage inverter with pulse-width modulation, and the presence of Butterworth filters does not introduce significant distortion and allows to obtain necessary phase voltage shapes in the generalized electric machine.
Optimization of Equipment Capacity of Power Park in Volzhskiy Branch of MPEI
Authors: Sultanov Makhsud , Zenina Elena , Zhelyaskova Olga , Erofeev Dmitry
Published: July 2021

The article describes the development of an innovative microgrid landfill on the territory of the branch of NRU MPEI in Volzhskiy. The power park is considered as a microgrid with traditional and renewable energy sources. The aim of this facility is to provide heat and electricity to the institute's building and a practical study of the operation and maintenance of power equipment. The types of cogeneration plants are defined. Possible variants of the equipment layout with the determination of the power factor of each unit are considered. Trigeneration is proposed for the profitable use of the thermal steam of the units, which will contribute to saving electricity for cooling the institute in the summer. By analogy with the mathematical theory of Sharpe-Markowitz and J. R. R. Tolkien a graph of the dependence of the cost of 1 kWh and the risk assessment of energy supply in % of all equipment layout options of each variant is constructed. Based on the obtained data, a conclusion is formed about the optimization of power equipment for the Power Park.
Development of a methodology for data validation in power systems using different types of measurements
Authors: Kovalenko Pavel Y. , Mukhin Valentin I. , Senyuk Mihail D.
Published: July 2021

In recent years, the technology of synchrophasor measurements has been introduced in power systems around the world. When managing a power system and predicting its operation conditions, the important task is to check the validity of power system data. At the same time, the traditional types of measurements, such as digital fault recorders and telemetry devices are still widely used. It is known that redundancy of measurements contributes to a more accurate solution of the data validation problem. It is useful to create a method for data validation in power systems, which could involve various types of measurements in order to increase the redundancy and, hence, the overall accuracy of measurements. This study presents some validity criteria that use the idea described above. The results of testing the proposed methodology on the substation model in Matlab software package are presented and discussed.
Prospects for the use of a microwave electromagnetic field for the creation of an ecological technology for the production of firing materials and the development of microwave energy
Authors: Zhenzhurist Irina
Published: July 2021

The article considers the causes of environmental problems in the energy sector. The increased demand for energy resources and the increasing shortage of natural fuels are leading to the search for renewable energy sources. The prospects of energy transmission by microwave radiation without wires as an alternative to traditional energy sources are considered. The article provides information on the results of research on obtaining a high level of energy transfer by a microwave beam from a geostationary orbit to the earth's surface in the near future, as well as developments in the field of creating a solar space power plant (SSP). The results of research on the sintering of inorganic substances in an electromagnetic field are presented, the prospects for this direction in materials science are considered. The results of sintering natural raw materials in a microwave field are considered. The formation of nanoscale phases in sintered compositions has been established. The effect of a low-melting mineralizing additive on the sintering process is shown. The increased strength characteristics of the samples obtained by high-speed firing in the microwave electromagnetic field, the prospects for developments in this direction for various types of materials are noted.
Vendor selection information system on the electronic trading platform for energy supply companies
Authors: Zaripova Rimma , Nikitin Alexander , Hadiullina Yulia , Pokaninova Elena , Kuznetsov Maxim
Published: July 2021

The main challenges for industrial companies today are to improve the competitiveness of their products and to adapt and respond quickly to changes in the external environment. Ensuring the effective functioning of an industrial enterprise is largely determined by its procurement activities, including the reliability and consistency of the procurement process. Relevance of the topic is conditioned by the fact that procurement is one of the main components in increasing of competitiveness and efficiency of the enterprise, as the major part of costs in the cost price of the finished products is concentrated exactly in procurement. Reducing costs in procurement is one of the ways to improve the efficiency of the enterprise. This advantage can be achieved through the introduction of modern information technologies, namely automation of the process of selecting suppliers on an electronic trading platform. For this purpose, an information system for selecting suppliers on the electronic trading platform has been developed, which enables a more transparent, fast, profitable and less costly selection of the cheapest and most suitable goods for the operation of energy supplying enterprises. Procurement activities are aimed at ensuring that the energy-supplying undertaking receives the right quantity and quality of raw materials, materials, goods and services at the right time, in the right place, from a reliable and trustworthy supplier with good service and at a favourable price. Automating the supplier selection process on an electronic platform is essential in today's market environment.
Analysis of the composition of alternative energy sources in the regional energy system
Authors: Yusupova Angela , Yusupov Baysangur , Debiyev Mayrbek , Masaev Suliman , Amkhaev Timur , Madaeva Anu
Published: July 2021

The regional authorities, solving energy issues via the development of small-scale energy capacities, enable more adaptive and economical solution of the problems of energy development at the regional level. Thus, one of the foundations of small-scale energy is the use of alternative energy sources. Formation of schemes and procedures for the development of regional energy modalities based on the active use of alternative energy sources is the objective of developing the energy industry, both at the regional level and throughout the country. In order to solve this problem, an analysis of all available alternative energy sources in the regional energy system is carried out. Although the discussion on this issue is extensive, special attention is paid to the analysis of the problems associated with the introduction and development of alternative energy systems. This article describes procedures for generating a set of global factors that can have a significant impact on the implementation or operation of alternative energy systems. Based on the systematic approach and the resulting composition of global factors, a composition of eighteen influencing factors was identified. The presence of a systemically complete set of indicators describing the factors of influence on the process of functioning of alternative energy systems in the region makes it possible to set and formalize a number of important ones. The descriptions of three interesting issues for the implementation and development of alternative energy systems are given in this paper. For future developments, we plan to list models of the issues, as well as to develop practices to overcome these issues.
Problems of Insulation Diagnostics of Power Equipment by the Method of Partial Discharges
Authors: Usachev A.E. , Kubarev A.Yu.
Published: July 2021

Target. High information value and reliability of diagnostics of isolation by partial discharges. Methods. Simulation of PD in Multisim and calculation of electrical fields of insulation defects by finite element method in the program ComSol. Results. A strong influence of the power supply on the value of voltage surge in case of emergency has been established. The method of adjustment of this influence is proposed. It was found that the oscillatory form of the PD is mainly determined not by the parameters of the insulation defect, but by the parameters of the energy object in which this defect is observed. Method for separation of aperiodic signal of PD from oscillatory component of system transient process in PD is proposed. It is shown that in operating turbogenerators and power transformers the unambiguous connection between the phase of PD occurrence and the voltage of PD occurrence is broken. Method of determination of PD occurrence place in slot part of turbogenerators is proposed. It is shown that in order to increase the reliability of comparing PD in polymer insulation of power cables of different voltage classes and geometric dimensions, when calibrating the measuring system, it is necessary to take into account the speed of propagation of the PD pulse through the cable and the capacity of the cable length unit. The concept of a corrective coefficient for calibration has been introduced and a method for determining it has been proposed. Conclusions. Taking into account the differences in PD parameters in real objects of the electric power industry, proposed in the article, from the parameters obtained in the standard laboratory model of the PD should increase the information and reliability of the PD method, as well as make it possible to conduct a comparative analysis of the results obtained under various observation conditions.
Experimental study of the control of operating modes of a plate feeder based on the frequency-controlled electric drive
Authors: Toirov Olimjon , Urokov Sardor , Mirkhonov Utkir , Afrisal Hadha , Jumaeva Dilnoza
Published: July 2021

An experimental study of the control of the operating modes of the plate feeder based on a frequency-controlled electric drive in the mining industry has been carried out. The graphs of measurements of the electrical parameters of the electric drive supplied from the frequency converter of the plastic feeder, instantaneous values of harmonic composition of voltage and current up to 50 harmonics, as well as changes in current and voltage harmonics over a period of 30 minutes were obtained. Measurement of oscillograms of voltage and current of each phase in operating mode and the moment of turning off and turning on the electric motor of the plastic feeder. The issues of control of starting modes of the plate feeder from frequency-controlled electric drives are considered. It has been determined that frequency start-up with the linear control law for the frequency of the plate feeder as a function of time and technological parameters are the most acceptable condition for starting modes.
The influence of changing resistance on the determination accuracy of short circuits in power lines
Authors: Nazarov Serdar , Kelov Gurbangulych , Gochyev Berdimyrat
Published: July 2021

In high-voltage electrical networks, the occurrence of short circuits leads to forced interruptions in the power supply of large consumers and disruptions in intersystem communications. More than 65% of all types of occurring short circuits are single-phase short circuits [1]. In a single-phase short circuits (SPSC), a change in the zero sequence resistance (ZSR) especially significantly affects the inaccuracy in detection of damage sites (DDS). When choosing DDS methods, preference is given to remote methods according to the parameters of the emergency conditions (PEC), which are recorded by special instruments or determined from the oscillograms of emergency conditions. The use of modern microprocessor-based relay protection and automation devices (RPA) [26] or emergency event recorders allow viewing the oscillograms of emergency events. In a branched 110 kV network with a complex configuration, the DDS accuracy is influenced by a change in the ZSR. Averaging of specific parameters often leads to erroneous results. The choice of one value from the oscillograms puts the maintenance personnel in difficulty. In the scientific work, the influence of changes in the ZSR on the accuracy of the DDS is considered. The changes in the ZSR are influenced by the position of the on-load voltage regulator (OLTC) switches of transformers with a grounded neutral. In the work, for a more accurate record of the specific parameters of the network, a calculation program has been compiled, which allows making changes in the calculated specific parameters of the network. To determine the short-circuit current from the oscillograms, it is proposed to determine the stable state of accidents in which the current value will be approximately the same. The analysis of the oscillograms of SPSC in 110-220 kV networks in the southern part of the electric power system of Turkmenistan has been carried out.
The forecasting power of the brand: contribution to the increase in the value of the company’s intangible assets
Authors: Sevostyanova Olesya , Petuhova Svetlana
Published: July 2021

The article is devoted to the study of the cost characteristics of brand power, determining and forecasting the revenue of companies generated by brand power. Under the influence of the growing role of the brand, there is now an increase in the range of using its valuation as the most important of the company’s intangible assets, including managing the business development strategy. It is proved that brand competitiveness becomes the most important component of the company’s overall competitiveness. Using the private V-RATIO method, the cash flow generated by the brand itself is determined, and sales volumes are calculated under the influence of brand and non-brand factors for the “Shoes of Russia” and “KARI” trading companies. The cost of the studied brands is calculated and the curve of falling brand strength without supporting measures is determined.
The Development of A Universal Transformer Housing of the Unit Transformer Substation 6-10 / 0.4 KV
Authors: Malygin Dmitry Vladimirovich , Borodin Maksim Vladimirovich , Belikov Roman Pavlovich , Mikhaylova Yulia Lyusievna , Shakurova Zumeyra Munirovna
Published: July 2021

The company group of the PJSC “ROSSETI” pays great attention to reducing occupational hazard at the facilities of the power grid complex. The analysis of the accidents in the branch of PJSC “IGDC of the Center”– “Orelenergo” revealed that transformer housings installed at the mast-type transformer substations 6-10 / 0.4 kV can’t fully provide the required safety level as they can be slightly raised even without using a special tool, and therefore one can stick his hands or some objects to the current-carrying parts of the transformer substation. According to the statistics of the damages at the mast-type transformer substations 6-10 / 0.4 kV various small animals and birds can enter the electrical installation through small slits between the housing and the transformer, which will lead to different emergency situations. To prevent the aforementioned negative consequences, a universal transformer housing was developed for a mast-type unit transformer substation (UTS) 6-10 / 0.4 kV. The offered design of the housing is universal, since it can be used for the transformers of various capacities; for its manufacture tools and materials with different characteristics can be used. At the same time, the installation of the developed housing will allow power grid companies to reduce occupational hazard, reduce the undersupply of electricity and increase the reliability of power supply to the agricultural consumers. The technical solution presented in the article can be applied for the mast-type UTS 6-10 / 0.4 kV in the post-Soviet countries.
Properties of heat induced blend gel of Peruvian squid (Dosidicus gigas) myofibril protein fortified with millet (Panicum miliaceum L.) flour
Authors: Wang Tian , Li Xuepeng , Xie Jing , Li Jianrong , Mi Geng
Published: July 2021

Weak gelation ability and simple nutrient composition of squid myofibril protein limits its further development in surimi production. Millet flour is rich in nutrients and has a good viscoelasticity after heating. Physicochemical properties of Peruvian squid myofibril protein based blend gel fortified with millet four were studied. Rheological test results showed that all blend gels exhibit solid-like characters. With the addition of millet flour, the composite modulus of all the samples showed a trend of decreasing first and then increasing. The minimum value appeared around 48oC. Moreover, it was found that gel strength, water holding capacity, hardness, gumminess and chewiness showed a trend of increasing at first and then decreasing. The blend gel with 4% millet flour addition exhibit good performance in those testing. The subsequent analysis of water distribution further explained and proved the mechanism. In summary, the blend gel of squid myofibril protein fortified with 4% of millet flour addition was considered the most suitable amount for enhancing the quality of blend gel.
Universal Adhesives- Different Curing Methods and Applications
Authors: Dong Wanying , Gu Xiaojing , Han Jianghao , You Liwen
Published: July 2021

The adhesive is a kind of material with good adhesion properties which could join objects by adhesion of surfaces via forces of adhesion and cohesion. There are many kinds of adhesives. This paper mainly classifies them by curing method, from UV curing and heat curing to moisture curing and microwave curing, and describes the corresponding mechanisms. Furthermore, it covers the advantages and disadvantages, application ranges, and related chemical compounds of different curing ways for adhesives. This can broaden our understandings of different ways of adhesive curing. Besides, it could also help us choose the most appropriate curing method according to different requirements in daily life.
Recent developments: self-healing polymers based on quadruple hydrogen bonds
Authors: Zhang Guangpu , Sun Zhe , Li Miaomiao
Published: July 2021

The microcrack of materials was inevitable in the process of transportation, storage and utilization, which may cause functional failure and resources waste. Inspired by nature, self-healing polymers have attracted significant attention owing to widespread applications in wearable electronics, cartilage replacement, coatings and elastomer. Compared with extrinsic healing, intrinsically healable polymers offer multiple self-healing by supramolecular reversible interactions, such as host-guest interactions, π-π stacking, ionic interactions and hydrogen-bonding. Self-healing polymers based on quadruple hydrogen bonds have been extensively investigated due to its high thermodynamic stability and rapid kinetic reversibility, and have been well developed for the past two decades. In this paper, the strategies and designs of self-repairing polymers based on quadruple hydrogen bond were classified and summarized, including main-chain self-healing polymers, side-chain self-healing polymers and supramolecular self-healing polymers. It is expected that quadruple hydrogen bonding can be construct more robust, highly tough, multi-stimuli-responsive, and fast self-healing supramolecular polymer, and is potential to be applied to numerous civilian and military fields in the future.
Sedimentary Facies of the Chang 2 Member of Yanchang Formation in Area A of Northern Shaanxi
Authors: Liu Yingzhi , Liu Yanyan , Chen Ying , Yang Shasha , Wang Bowang
Published: July 2021

In order to promote the rolling exploration and development of oil reservoirs in northern Shaanxi, a fine study of sedimentary facies in area A has been carried out. Using core and logging data, on the basis of identifying different levels of sequence interfaces and lake flooding, the Chang 2 Member in Area A was divided into two base level cycles, and a high-resolution sequence stratigraphic correlation was established. On the basis of core description, the analysis of single-well sedimentary facies, continuous-well sedimentary facies and planar sedimentary facies are carried out. It is believed that the Chang 2 member of the study area is a delta plain deposit, dominated by distributary channels, inter-distributary depressions, and natural dike microfacies. There are two to three main rivers in the study area. Both the vertical and the plane show that the length of Chang 22 sand bodies is more developed than the length of Chang 21 sand bodies. Among the three small layers of Chang 22, Chang 221 sand body is relatively well developed, and the channel width and thickness are large, making it the most favorable reservoir.
Forecast China’s monthly urban fixed asset investment based on the ARIMA model
Authors: Yuan Jiangle , Li Yaning , Li Yayu
Published: July 2021

In recent years, as China’s urbanization level has risen, China’s urban fixed asset investment has also been rising. Judging from monthly data, China’s urban fixed asset investment has shown a volatile upward trend, with an obvious 11-month cycle. And in each cycle, the fluctuation range of the investment amount is getting larger. This paper uses an ARIMA model with an additive seasonal effect to fit the monthly urban fixed asset investment sequence and predict the future investment. In the end, this paper established a fitting model for China’s urban fixed asset investment, and obtained a good forecasting effect.
Study on the Fatigue Failure Law of Gas Storage Caprock Under Periodic Injection and Production
Authors: Lingyan Liu , Wenman Mu , Yujia Zhai
Published: July 2021

Whether qualitative or quantitative, whether macroscopic or microscopic, Predecessors' research on the sealing ability of caprocks is concentrated on the static model of the caprock. A few scholars have also proposed the sealability evaluations of the caprock dynamic evolution process, they are all aimed at the dynamic evolution of geological historical periods, and there are few studies on the sealability of gas storage caprocks under periodic injection and production. In this paper, the characteristics of stress and strain under alternating loads of rock and non-rock materials are investigated and experimentally studied to clarify the law of fatigue failure of gas storage caprocks under periodic injection-production. The results show that it is possible that the microcracks may develop and propagate in the rock after the gas storage has experienced many periodic injections and productions, when the stress is far less than the rock strength limit, And then a macroscopic deformation is formed. The accumulated plastic deformation of the rock will increase, and the plastic deformation rate will gradually decrease, as the number of injection and production increases.
Research Hotspots and Evolution of Fusion of Blockchain and Supply Chain in China Based on Visualization Analysis
Authors: Liang Xuedong , Sun Jinghong
Published: July 2021

Based on 837 literatures of CNKI from 2015 to 2020, this paper conducts visualization analysis about domestic fusion of blockchain and supply chain with the utilization of Citespace, and reveal the research hotspots in the field of fusion of blockchain and supply chain in the past five years. The study finds that, firstly, China Finance, Southwest Finance, and Business & Economy are the journals with higher quantity of publication in this field; secondly, Song Hua and Xu Peng are the leading scholars in this research area; thirdly, the research institutions in this field are mainly concentrated in the School of Economics and Management, Law School and School of Information Management in major universities; fourthly, application scenarios, technology development, applied agent and fund are the research hotspots in this area. This study reveals the basic dynamics of domestic fusion of blockchain and supply chain research in the past five years, which not only can promote the theoretical development of this field, but also point out the research hotspots and future research direction for scholars in this area, and provide reference and reference for all walks of life who plans to enter this field.
Analysis and Solution of Condensation Phenomenon in Ring Main Unit
Authors: Shi Kexin , Yang Junjie
Published: July 2021

The current condensation phenomenon inside the ring main unit will cause corrosion of components, short circuits, partial discharges and other problems, which will seriously affect the safety and durability of power supply. In response to the above problems, this paper designs and builds a condensation test platform, conducts an experimental analysis on the factors that cause condensation, and combines the conclusions drawn to propose a remote monitoring system for anti-condensation. Operation and maintenance personnel can use a small program to remotely monitor the internal environment of the ring network cabinet and deal with condensation in a timely manner. The application of this system provides great convenience for the operation and maintenance personnel, and also has a significant impact on the monitoring and maintenance of the anti-condensation of the ring network cabinet.
Reservoir characteristics of Chang 2 Member of Yanchang Formation in Area A, Ordos Basin
Authors: Jing Yajie , Zhang Zhiwu , Xu Peng , Yang Shasha
Published: July 2021

With the continuous enhancement of exploration and development in the Ordos Basin, in-depth research has been carried out on the petrological and reservoir characteristics of Chang 2 reservoir in Area A, which provides a geological basis for the efficient development of oil reservoirs. Comprehensive use of reservoir sandstone thin section identification casting analysis, mercury intrusion analysis, logging analysis and other methods to systematically study the petrological characteristics, pore characteristics and reservoir physical properties of Chang 2 reservoir in Area A. The results show that the reservoirs in the study area are dominated by fine-grained sandstones, with low component maturity and high structural maturity. They are all medium-low porosity, low-permeability and ultra-low permeability reservoirs. Primary intergranular pores and residual intergranular pores are developed, the reservoir drainage pressure is low, which is good-medium, and the mercury removal efficiency is high, indicating that the reservoir has good storage performance and seepage properties.
A Visual Study of Jiangxi Music Non-legacy Knowledge Based on VR Technology
Authors: Liu Chuanli , Cai Chunbao , Wei Lizhi
Published: July 2021

As the development of society and the innovation of science and technology, VR technology, as a new product of the 21st century, brings us not only shock, but a fusion of innovation. As a hot spot in this era, VR technology is also called “spiritual technology”. This technology makes a virtual world by computer, makes the diversified information merge into a three-dimensional body information, through the equipment, can make people in a virtual real environment can not extricate themselves. The progress of science and technology has always surprised us.” VR technology “is a comprehensive innovation for all walks of life. How to make Jiangxi music non-legacy knowledge get attention again, VR technology should be a breakthrough.
The Review of Biosensor and its Application in the Diagnosis of COVID-19
Authors: Wu Jiyun , Wu Qiuyao
Published: July 2021

The objective of this article is to summarize the available technologies for biosensing applications in COVID-19. The article is divided into three parts, an introduction to biosensing technologies, applications of mainstream biosensing technologies and a review of biosensing applications in COVID-19. The introduction of biosensors presents the history of inventing the biosensing technology, which refers to the ISFET. The resonant biosensor with the example of MEMS. the principle of optical biosensor, and the thermal biosensor. In the second part, the main use of biosensing techniques, it was discussed the field of the food industry, environmental monitoring, and the medical industry. In the part of biosensor application in COVID-19, it was mentioned that the technique of POCT, the use of RT-LAMP-NBS in the early detection in China, and the use in gRT-PCR for the detection of the DNA code to determine the presence of pathogen of COVLD-19 in the human body.