bluuebunny/crossref_metadata_2025 huggingface dataset:
Algorithmic monoculture and social welfare
Authors: Kleinberg Jon , Raghavan Manish
Published: May 2021

Significance

Algorithmic monoculture is a growing concern in the use of algorithms for high-stakes screening decisions in areas such as employment and lending. If many firms use the same algorithm, even if it is more accurate than the alternatives, the resulting “monoculture” may be susceptible to correlated failures, much as a monocultural system is in biological settings. To investigate this concern, we develop a model of selection under monoculture. We find that even without any assumption of shocks or correlated failures—i.e., under “normal operations”—the quality of decisions may decrease when multiple firms use the same algorithm. Thus, the introduction of a more accurate algorithm may decrease social welfare—a kind of “Braess’ paradox” for algorithmic decision-making.
DLL1 orchestrates CD8+T cells to induce long-term vascular normalization and tumor regression
Authors: Zhang Naidong , Yin Rongping , Zhou Pei , Liu Xiaomei , Fan Peng , Qian Long , Dong Li , Zhang Chenglin , Zheng Xichen , Deng Shengming , Kuai Jiajie , Liu Zhenhua , Jiang Wen , Wang Xiaohua , Wu Depei , Huang Yuhui
Published: May 2021

Significance

Cancer immunotherapy demonstrates durable clinical efficacy but only in a small percentage of cancer patients. The aberrant tumor blood vessels and resulting hypoxic tumor microenvironment are major obstacles to hinder cancer immunotherapy. Tumor vascular normalization is a promising strategy to overcome these hindrances; however, the normalizing effects induced by current available approaches are often transient, limiting its therapeutic benefits. Here, we show that Delta-like 1 (DLL1) can induce long-term tumor vascular normalization, alleviate the hypoxia and immunosuppression within the tumor microenvironment, and prolong survival of anti-CTLA4 therapy. This study suggests that DLL1 is a potential target to persistently normalize the tumor microenvironment to enhance cancer immunotherapy.
Four-dimensional aspects of tight contact 3-manifolds
Authors: Hedden Matthew , Raoux Katherine
Published: May 2021

Significance

A surprising result of the 20th century is that the classification problem for four-dimensional spaces called smooth 4-manifolds is more subtle and difficult than the analogous problem for both lower- and higher-dimensional spaces. Classifying 4-manifolds is intimately connected to the study of surfaces embedded therein. This article proves results and proposes conjectures relating such surfaces in 4-manifolds to three-dimensional geometric structures called contact structures.
Membrane voltage-dependent activation mechanism of the bacterial flagellar protein export apparatus
Authors: Minamino Tohru , Morimoto Yusuke V. , Kinoshita Miki , Namba Keiichi
Published: May 2021

Significance

The transmembrane electrical potential difference (Δψ), which is defined as membrane voltage, is used as the energy for many biological activities. For construction of the bacterial flagella on the cell surface, a specialized protein transporter utilizes Δψ to drive proton-coupled protein export, but it remains unknown how. Here, we report that an inactive flagellar protein transporter can be activated by an increase in Δψ above a threshold value through an interaction between FliJ and the transmembrane proton channel protein FlhA. Following activation, the protein transporter conducts protons through the FlhA channel to drive flagellar protein export. This report describes a Δψ-dependent activation mechanism used for a biological function other than voltage-gated ion channels.
Unravelling the mechanisms controlling heme supply and demand
Authors: Leung Galvin C.-H. , Fung Simon S.-P. , Gallio Andrea E. , Blore Robert , Alibhai Dominic , Raven Emma L. , Hudson Andrew J.
Published: May 2021

Significance

Heme is essential for the survival of virtually all living systems and is involved in many fundamental biological processes. It is also implicated as a signaling/regulatory molecule and must be mobilized in response to cellular demands. This presents a complex logistical problem: heme cannot simply diffuse around cells because it is both insoluble and cytotoxic. We show that the cell exhibits exquisite control over release of heme by limiting its availability to one molecule or less within cellular compartments. We suggest an exchange mechanism between protein partners to control supply and demand. Such a mechanism would provide an in-built buffering capacity for heme, enable cells to hoard supplies of heme, and protect the cell against the undesirable effects of heme.
Developing a multilingual dictionary of touristic-cultural terms (with Croatian as the source language)
Authors: Lončar Ivana , Pavić Pintarić Anita
Published: May 2021

This paper deals with the challenge of developing a multilingual dictionary of touristic-cultural terms with Croatian as the source language, based on the principles of lexicography which include the rigorous metalexicographic methodology and the practical needs of users (tourism professionals, managers, teachers, and students of philological careers, as well as those related to tourism and hospitality). The project, broadly speaking, is divided into three phases. The current, first phase of research includes the elaboration of a corpus comprising a series of terms, simple units, or expressions from different areas with special attention to the realia of the source language, which do not exist in the target languages (German, English, Spanish and others). The second phase will involve the lemmatization of entries, their classification, the elaboration of appendices, and the modeling of parameters and definers that will be used in the lexicographical definition. The third phase covers the elaboration of the microstructure. At this stage, special emphasis will be placed on the type of lexicographic definitions (and their combinations) that will be used in the dictionary. It is expected that the dictionary would have photographic materials under copyright.
Gender identification in the portrayal of female roles in the remakes of American TV series in Turkey
Authors: Sancaktaroğlu Bozkurt Sinem , Okyayuz Ayşe Şirin
Published: May 2021

The transfer of stories across borders in translation, adaptation, or remake is a common phenomenon in the globalized world. In Turkey, translating foreign audiovisual products to enrich the cultural repertoire has been a prominent practice. Focusing on the portrayal of female characters in contemporary remakes of several American TV series aired on primetime national channels in Turkey, this study aims to pinpoint audiovisual norms that guide the “transfer” of these characters for Turkish audience. The analysis seeks to exemplify how remakes deconstruct, reformulate, and thus (re)construct the representations of women’s identities in Turkey. The study initially concentrates on remakes as a genre, moves on to outline the practice in Turkey, and analyzes the reformulation of gender roles in line with Turkish societal norms within the scope of audiovisual translation from the gender perspective. The study singles out a series of norms that seem to guide and color the transfer of female characters in the remakes for the Turkish audience, elaborates on why it is necessary, and suggests the implications of such practices.
Negotiating inclusion of gender and sexual diversity through a process of feminist translation in Quebec
Authors: Bessaïh Nesrine
Published: May 2021

According to French grammatical rules the masculine prevails over the feminine. In Quebec since the 1980s, an inclusive, “non-sexist writing,” aimed at making the feminine visible, has been promoted by women’s activist groups and has been adopted in most governmental publications. Recently, a renewal of the notion of gender manifests itself through an emerging definition of inclusive writing as “neutral writing,” aimed at neutralizing gender in the French language. In this context, a feminist collective has undertaken the translation into French ofOur Bodies, Ourselves, a major reference book on sexual and reproductive health. What effects has the coexistence of these two trends of feminist inclusive writing had on the process of constructing and writing this book and on the terminological choices made by the collective of translators? This case study showcases how the translation process opens a space for rethinking linguistic practices around gender.
Aged hematopoietic stem cells are refractory to bloodborne systemic rejuvenation interventions
Authors: Ho Theodore T. , Dellorusso Paul V. , Verovskaya Evgenia V. , Bakker Sietske T. , Flach Johanna , Smith Lucas K. , Ventura Patrick B. , Lansinger Olivia M. , Hérault Aurélie , Zhang Si Yi , Kang Yoon-A , Mitchell Carl A. , Villeda Saul A. , Passegué Emmanuelle
Published: May 2021

While young blood can restore many aged tissues, its effects on the aged blood system itself and old hematopoietic stem cells (HSCs) have not been determined. Here, we used transplantation, parabiosis, plasma transfer, exercise, calorie restriction, and aging mutant mice to understand the effects of age-regulated systemic factors on HSCs and their bone marrow (BM) niche. We found that neither exposure to young blood, nor long-term residence in young niches after parabiont separation, nor direct heterochronic transplantation had any observable rejuvenating effects on old HSCs. Likewise, exercise and calorie restriction did not improve old HSC function, nor old BM niches. Conversely, young HSCs were not affected by systemic pro-aging conditions, and HSC function was not impacted by mutations influencing organismal aging in established long-lived or progeroid genetic models. Therefore, the blood system that carries factors with either rejuvenating or pro-aging properties for many other tissues is itself refractory to those factors.
A reconfigurable and portable acoustofluidic system based on flexible printed circuit board for the manipulation of microspheres
Authors: Mikhaylov Roman , Martin Mercedes Stringer , Dumcius Povilas , Wang Hanlin , Wu Fangda , Zhang Xiaoyan , Akhimien Victory , Sun Chao , Clayton Aled , Fu Yongqing , Ye Lin , Dong Zhiqiang , Wu Zhenlin , Yang Xin
Published: May 2021

Acoustofluidic devices based on surface acoustic waves (SAWs) have been widely applied in biomedical research for the manipulation and separation of cells. In this work, we develop an accessible manufacturing process to fabricate an acoustofluidic device consisting of a SAW interdigital transducer (IDT) and a polydimethylsiloxane microchannel. The IDT is manufactured using a flexible printed circuit board pre-patterned with interdigital electrodes that is mechanically coupled with a piezoelectric substrate. A new microchannel moulding technique is realised by 3D printing on glass slides and is demonstrated by constructing the microchannel for the acoustofluidic device. The flexible clamping mechanism, used to construct the device, allows the reconfigurable binding between the IDT and the microchannel. This unique construction makes the acoustofluidic device capable of adjusting the angle between the microchannel and the SAW propagation, without refabrication, via either rotating the IDT or the microchannel. The angle adjustment is demonstrated by setting the polystyrene microsphere aggregation angle to −5°, 0°, 6°, and 15°. Acoustic energy density measurements demonstrate the velocity of microsphere aggregation in the device can be accurately controlled by the input power. The manufacturing process has the advantages of reconfigurability and rapid-prototyping to facilitate preparing acoustofluidic devices for wider applications.
Slow stretched-exponential and fast compressed-exponential relaxation from local event dynamics
Authors: Trachenko K , Zaccone A
Published: May 2021

We propose an atomistic model for correlated particle dynamics in liquids and glasses predicting both slow stretched-exponential relaxation (SER) and fast compressed-exponential relaxation (CER). The model is based on the key concept of elastically interacting local relaxation events. SER is related to slowing down of dynamics of local relaxation events as a result of this interaction, whereas CER is related to the avalanche-like dynamics in the low-temperature glass state. The model predicts temperature dependence of SER and CER seen experimentally and recovers the simple, Debye, exponential decay at high temperature. Finally, we reproduce SER to CER crossover across the glass transition recently observed in metallic glasses.
Trajectory and factors of radiation risk perception of students aged 10–12 years at the time of the Fukushima Daiichi Nuclear Power Station accident
Authors: Yasui Kiyotaka , Takebayashi Yoshitake , Motoya Ryo , Aoki Shuntaro , Horiuchi Teruko , Hatsuzawa Toshio , Nakano Kazunori , Ohba Takashi , Yoshida Kazuki , Midorikawa Sanae , Ohtsuru Akira , Murakami Michio
Published: May 2021

Various studies have investigated radiation risk perceptions after the accident at the Fukushima Daiichi Nuclear Power Station. However, student surveys are limited. This study aimed to investigate the perception of radiation risk among students aged 18–20 years who were in the 5th and 6th grades of elementary school at the time of the accident. We surveyed students in the Fukushima Prefecture and outside the prefecture. Out of all the data, 59% of the respondents were living in the Fukushima Prefecture at the time of the accident and 41% outside the prefecture. Trajectory analysis showed that changes in anxiety levels over time since 2011 could be divided into five classes: (a) the anxiety was the highest, and this tendency persisted. (b) High at the beginning, but decreased more quickly than class 1. (c) High at the beginning, but it diminished quickly. (d) Not high, but did not diminish easily in later years. (e) Low from the beginning, and persisted. Multinomial logistic analysis showed that among students living outside the prefecture at the time of the accident, a significantly higher proportion was in groups 4 and 5 than in group 2. A significant proportion of boys were present in groups 3, 4 and 5. A significant proportion of students whose current educational institutions were inside the prefecture were present in group 3. The level of anxiety was associated with the academic course, but not with subjective knowledge of radiation. In contrast, in the qualitative analysis of the free text, 31% considered ‘knowledge about radiation’ as the reason for the reduction in anxiety level. At the time of the investigation, most young people were not anxious about radiation. However, approximately 20% still had strong anxiety. We established that continuous risk communication is necessary. Furthermore, that stabilization and support related to life in general is important.
Localized Wannier function based tight-binding models for two-dimensional allotropes of bismuth
Authors: Li Qile , Smith Jackson S , Yin Yuefeng , Wang Chutian , Klymenko Mykhailo V , Cole Jared H , Medhekar Nikhil V
Published: May 2021

With its monoelemental composition, various crystalline forms and an inherently strong spin–orbit coupling, bismuth has been regarded as an ideal prototype material to expand our understanding of topological electronic structures. In particular, two-dimensional bismuth thin films have attracted a growing interest due to potential applications in topological transistors and spintronics. This calls for an effective physical model to give an accurate interpretation of the novel topological phenomena shown by two-dimensional bismuth. However, the conventional semi-empirical approach of adapting bulk bismuth hoppings fails to capture the topological features of two-dimensional bismuth allotropes because the electronic band topology is heavily influenced by crystalline symmetries. Here we provide a new parameterization using localized Wannier functions derived from the Bloch states in first-principles calculations. We construct new tight-binding models for three types of two-dimensional bismuth allotropes: a Bi (111) bilayer, bismuthene and a Bi (110) bilayer. We demonstrate that our tight-binding models can successfully reproduce the electronic and topological features of these two-dimensional allotropes. Moreover, these tight-binding models can be used to explain the physical origin of the occurrence of novel band topology and the perturbation effects in these bismuth allotropes. In addition, these models can serve as a starting point for investigating the electron/spin transport and electromagnetic response in low-dimensional topological devices.
Research on nature of petroleum bitumen interaction with components of complex modifier
Authors: Belyaev P S , Frolov V A , Varepo L G , Belyaev V P , Bezzateeva E G
Published: May 2021

The paper deals with petroleum road bitumen interacting with the components of a complex modifier. They are high-pressure polyethylene, thermoelastoplast, polymer packaging waste and surfactants. The analysis of changes are presented in the physical and mechanical properties of binders for road pavements obtained by Fourier-IR spectroscopy, optical methods and standard equipment for measuring the qualitative indicators of road binders based on petroleum bitumen.
Formation of a mixture with the specified quality characteristics from the available small batches of multicomponent mixtures, provided that the total batch of the largest volume is created
Authors: Evseev A V , Alekseev A A , Kasatkin G V , Proskuriakov N E
Published: May 2021

Statements, algorithms of the decision and the corresponding examples of tasks of forming of new mixes with the set characteristics or closest to the set characteristics from the available parties of multicomponent mixtures are given in work. The specified tasks have arisen in the course of the analysis of problem of drawing up by livestock complexes of the balanced nutritious mixes from the available small consignments of mixes. Solutions of the given tasks can be demanded also in other spheres of production. For example, in metallurgy at production of alloys, pharmacology at production of drugs.
A software-hardware unit for studying the output characteristic of MEMS pressure sensors and its linearization
Authors: Kabanov A A , Esimkhanova A M , Nikonova G V , Sirotenko N Yu , Soloviev V V
Published: May 2021

The paper presents the development of a linearization algorithm of the output parameters of the sensors based on the circuits that determine the static characteristics of the correction transducers, ensuring the linearity of the general conversion function with a given accuracy. Simulation modeling of correcting the output parameters of MEMS pressure sensors has been carried out. The qualitative characteristics of the measuring system are determined via providing the sensors with a means for determining the degree of reliability of their output data using a virtual exemplary tool. A technique for calibrating and linearizing the output characteristic of an analog MEMS pressure sensor has been developed. An algorithm for polynomial approximation of the nonlinear output characteristic of the sensor and a method for its implementation in Lab View software environment (by National Instruments) are presented. Virtual instruments developed in Lab View software environment have been the basis of software-hardware means for monitoring and processing of measuring data. The developed methodology and means of automation of measuring processes with the use of virtual devices made it possible to make the process of correcting the output parameters of sensors autonomous, independent of stationary measuring devices and debugging tools.
Features of high-precision measurements of laser beam lateral displacements in hybrid 3D scanning fiber-optic measuring heads
Authors: Leun E V
Published: May 2021

The article discusses the features of using a feedback sensor based on an acousto-optical (AO) laser measuring system (LMS) for high-precision control of transverse displacements of the laser beam in hybrid 3D scanning adaptive fiber-optic measuring heads. Scanning circular movements of a laser beam with a frequency of 1, 5, 10 kHz, formed by a miniature fiber-optic piezoscanner, are considered. Two working sections are created from the circular trajectory formed by a moving laser beam, which are its orthogonal projections, and the current position of the optical spot of each of them is measured in AO LMS. The frequency and accuracy parameters of the AO LMS for traveling ultrasonic waves excited in the AO modulator used as a measure (ruler) are analyzed. The dependences on the length of the ultrasonic waves of the Doppler frequency range, the signal-to-noise ratio of the photodetector, the phase error and the error of transverse displacements, the number of distinguishable angular deviations within 180°, and the spatial resolution are determined and analyzed.
Algorithm for testing digital substation protection devices in conditions of network distortions in the process bus
Authors: Lysenko O A , Simakov A V , Kharlamov V V
Published: May 2021

The article deals with the digital substation equipment maintenance. Equipping the electrical substations secondary circuits with intelligent electronic devices (IEDs) is an important direction in the electric power industry digital transformation. The purpose of the work is to develop an algorithm for testing digital substation protection devices for the influence of network distortions in the process bus. The tasks are to identify the main distortion types, determine the maintenance content and test it. The need to expand the existing service is determined, the maintenance algorithm is developed and a pilot test of the network distortions effect on the IED protection functions is performed.
Results of a theoretical and experimental research of a vertical hopper-feeding device with rollers for flat and close-to-equal-sized parts with implicit asymmetry
Authors: Pantyukhina E V , Preis V V , Puzikov I V , Dyakova E V
Published: May 2021

The paper considers the proposed design and a developed on the basis of an integrated approach mathematical model of the feed rate of a vertical hopper-feeding device with rollers for flat and close to equidimensional parts of the shape of bodies of rotation with asymmetry at the ends of two types: with a cylindrical stepped end and an end in the form of a truncated cone. The developed model, the adequacy and correctness of which is confirmed by the results of experimental studies, allows at the design stage with high precision for practice to determine the parameters of the feeding device, which will ensure the required feed rate and reliability of automatic machines and lines.
Identification of causal relationships of risk assessment
Authors: Arifjanov A Sh , Muhamediyeva D T , Khasanov U U
Published: May 2021

The paper deals with the identification of the cause-and-effect relationship of risk assessment with an indistinctly specified initial information. An example of a risk assessment task is the operation of a storage facility for the transport or storage of industrial products. A fire with different parameters must be considered as an anomalous external influence. The storage response, measured by the assessment of the safety of the content and its non-penetration into the external environment, can vary depending on the current state of the system, for example, the degree of possible damage in emergency conditions.
Estimate and asymptotic of the solution for the p-Laplacian parabolic equation double non-linear type with damping
Authors: Aripov M M , Djabbarov O R
Published: May 2021

In this article, using the solution to the Hamilton-Jacobi equation, we allegedly investigate the estimate and asymptotic of solutions for a parabolic equation with double nonlinearity with damping with a variable coefficient. An estimate for the weak solution and the asymptotic of regular, unbounded and finite solutions of the stationary equation are obtained. The condition for spatial localization of the solution to the Cauchy problem is found.
Neuro-fuzzy algorithm for clustering multidimensional objects in conditions of incomplete data
Authors: Khidirova Ch M , Sadikova Sh Sh , Nashvandova G M , Mirzaeva S E
Published: May 2021

The paper is considered development of fuzzy expert system model for identifying faults in complex systems using data mining methods based on searching for hidden patterns in databases. The use of neural network technologies makes it possible to detect nonlinear dependencies of input and output data, improve the quality of an objective assessment of the state of complex technical objects, which ultimately will reduce the number of emergency situations during operation. A method is proposed for identifying the optimal number of fuzzy clusters in the space of training examples and determining, on their basis, the parameters of the membership functions for the input variables and inference results. Considered a neuro-fuzzy algorithm for clustering multidimensional objects in conditions of incompleteness and fuzzy initial information.
Calculation of profiled flooring using the mid-surface equation of the orthotropic plate
Authors: Makeev S A , Komlev A A , Makarov S E , Makarova I D
Published: May 2021

Steel profiled flooring is a structurally orthotropic material, since its orthotropy is not due to the material properties, but to the cross-sectional shape obtained at the production stage. Taking into account the orthotropic properties of the profiled flooring during the calculation is extremely rare, since it is a laborious process. A method is proposed for calculating profiled flooring taking into account its orthotropic properties, which is implemented in various computational software systems. The results of calculations in the Matlab package and the PC Lira-CAD are presented.
Imitation modeling of passenger traffic delivery activities
Authors: Muhamediyeva D K , Mirzaraxmedov S Sh
Published: May 2021

In this paper, the concept of building a new route network is investigated. The guiding idea of the concept is the functioning of transport as a coherent system. Under the given conditions, it is impossible to organize the stable operation of the passenger transport complex without eliminating the existing contradictions. In order to establish a balance of interests of all cooperating parties, a mechanism for regulating the route network is proposed in the work, the calculation of which makes it possible to select the type of vehicle on the route, as well as calculate the number of flights, based on the condition of achieving a break-even transport process for carriers of various forms of ownership.
Generic complexity of solving of equations in finite groups, semigroups and fields
Authors: Rybalov Alexander , Shevlyakov Artem
Published: May 2021

The paper is devoted by investigation of generic complexity of the algorithmic problem of solving of systems of equations in finite groups, finite semigroups and finite fields. We show that if this problem is intractable in the worst case and P = BPP, then there is no polynomial strongly generic algorithm, which solves it. The first author is supported by Russian Science Foundation, grant 19-11-00209. The second author is supported by Russian Science Foundation, grant 18-71-10028.
On mutual influence of emitters in directivity optimization of shortwave phased antenna arrays
Authors: Tiunin N N
Published: May 2021

The problem of short wave phased antenna arrays optimization was formulated as a quadratic programming problem. BARON solver was applied to retrieve a solution. Research of total gain dependency on frequency and density of counterweights system was performed.
Domains identification by the parameter values in multidimensional space
Authors: Zykin S V , Zykin V S
Published: May 2021

As a result of cluster and discriminant data analysis, the objects are distributed among different classes represented in the multidimensional space of parameter values. At the next stage, it is relevant to use the results obtained in various applications. The most frequently solved task is the diagnostics of a newly received object when the class of the object is determined through parameter values. In terms of a data view model, the problem can be reduced to determining a domain in parameter space, the new object belonging to this domain. The solution to this problem depends on the way the data analysis results are described and presented. Previously the graphic data model was considered to describe the domains separated by surfaces in the multidimensional space. Moreover, a constructive approach was proposed to describe an error in the representation of the boundaries, making it possible to take into account the experimental data errors. The mathematical model proposed in the given article is used to develop a domain identification algorithm by the parameter values in the multidimensional space. The proof of correctness and the estimation of computational complexity are provided for the algorithm. The results obtained make it possible to use the algorithm to calculate various characteristics of objects: state, intervals of existence, etc.
Features of practical application of electric power system’s stability estimation methods
Authors: Bubnov A V , Barskov V V , Kirichenko A N , Schekochikhin A V , Malgin G V
Published: May 2021

Timeliness of the topic is conditioned by the need to keep up ample of static and transient stability margins in modern electrical power systems. Object of an article is to give a determination of present methods of evaluating damping of systems with synchronous machines, in the context of their effectiveness. And also to estimate the effectiveness of these methods in the performance of the task concerned with selecting of best settings of automatic excitation regulators of synchronous generators. This analysis led us to the conclusions, in particular, about possibility to apply the root locus methods in estimating stability of electrical power systems, and also about genericity of the matrix method with the use of QR-algorithm, which is widely used in practice of calculating stability.
Forecasting electric power consumption of technocenosis objects on the basis of values from transformed vector rank distribution
Authors: Kivchun O R
Published: May 2021

The article examines a technique for predicting the electric power consumption of technocenosis objects on the basis of the values of the transformed vector rank distribution. This technique includes the following stages: preparing data on electric power consumption, calculating an additional resource for technocenosis objects, forming transformed rank distribution and forecasting its values. The theoretical basis of the methodology was formed by the tenets of the theory of vector rank analysis, the methodology of functional rank analysis and the theory of mathematical statistics, as well as the concepts “technocenosis”, “MS-cenosis” and “bifurcation”. Its distinctive feature is the possibility to take into account the external control effect of a higher power system-MC-cenosis by adding or deducting an additional resource calculated using the system of transformed vector rank distributions. The additional resource is the difference between the values of the technocenosis located on the vector rank distribution of the higher MC-cenosis and the lower permissible value of the lower boundary of permissible values. The presented technique can be implemented in software and hardware complexes and situational centers for electric power consumption control in the area, energy system, transport network complex, large infrastructures and enterprises. The results will significantly supplement the methods of resource management for large infrastructure and energy facilities and form a resource consumption plan individually for each object.
Investigation of transients in a submersible electric motor with a downhole compensator
Authors: Markova A A , Kopyrin V A , Deneko M V , Khamitov R N , Logunov A V
Published: May 2021

Currently, the energy efficiency improving into the oil production is an important task. The main electricity consumer in the electrical complex structure of the electric centrifugal pumps’ installation is a submersible asynchronous electric motor. The power factor of these electric motors varies from 0.75 to 0.85. It leads to the losses’ increasing in the conductive elements of the complex. The use of downhole reactive power compensators is the most potential way to increase the power factor into the submersible asynchronous electric motors. In the course of pilot tests there are some cases of the protection devices for downhole compensators’ false triggering. It is recorded when the control station is switched off. It leads to the energy efficiency decreasing into the oil production. The purpose of this study is to research the transients in a submerged asynchronous electric motor equipped by the downhole compensator when the power supply is switched off. The task of the study is to determine the transient process’ parameters, in order to prevent false triggering of the downhole compensator protection devices. Simulation modeling of a submerged electric motor with a downhole compensator is performed in the Matlab Simulink. A simulation model of a submerged electric motor with a downhole compensator is developed to study transients when the power supply is switched off. The characteristics for the transient process of the voltage and current into the downhole compensator are obtained during the simulation modeling. The current surge for the capacitors’ discharge of the downhole compensator is 260.7% relative to the rated current at the time of the power supply disconnection. Prevention measures off false triggering for automatic shutdown devices of the downhole compensator are proposed.
Improvement of the methodology for assessing the quality of the traction motor collector repair
Authors: Shkodun P K
Published: May 2021

The data of the traction motors collector profiles were obtained experimentally. A traction motors profile control device was used to measure the traction motors profile. The spatial spectra of the collector profile harmonics are calculated. The spatial spectrum of the traction motors profile is divided into three ranges: the first range characterizes the macroroughness of the collector, the second range determines the roughness of the traction motors profile of average values, the third range characterizes the microroughness of the traction motors profile. The amplitude of the harmonics of the first and second frequency ranges significantly decreases after the repair of the traction motor collector. Linear correlations have been established between the range of the reconstructed profile with a limited number of harmonics and the root mean square value. It is proposed to use the values of the amplitude of the reconstructed signal of the collector profile with a limited number of harmonics (three ranges). The proposed diagnostic parameters of the recovered signal swing for three ranges make it possible to assess the quality of the repair performed. The parameters allow to refine the methodology for diagnosing the technical condition of the traction motors profile using objective monitoring tools.
Development of mathematical models for the short-term forecasting of daily consumption schedules of active power by Moscow
Authors: Vyalkova S A , Kornykova O , Nadtoka I
Published: May 2021

The present article presents the results of research into solving the problem of increasing the accuracy of forecasting power consumption. The purpose of these studies is to develop mathematical models for short-term forecasting of daily schedules of active power consumption in Moscow, taking into account meteorological factors. Research has been carried out on four predictive models based on singular spectral analysis (SSA), least-squares method, trigonometric interpolation, neural and neural fuzzy networks (NFN). It is shown that the NFN and hybrid model based on MSSA and NFN has the smallest error.
The basics of choosing the composition of complex modifiers
Authors: Eremin E N
Published: May 2021

Based on the analysis of the thermodynamic conditions of stability of the process of heterogeneous nucleation of phases in the melt, it is shown that the growth of the solid phase on the substrate is determined by the properties of the transition layer, which should provide the maximum increment in the chemical potential that changes the dielectric constant and density of the component.

On the basis of the analysis, the criteria for the selection of complex modifiers, consisting of exogenous refractory particles-inoculators and activating additives – inoculators and activating additives-protectors. To intensify heterogeneous nucleation in the melt, inoculators should be selected based on the conditions of resistance to dissolution and the highest electrical conductivity, while catalytic activating additives – from the condition of their affinity for particles of inoculators, contributing to the completion of their crystal lattices and the ability to ensure the formation of a transition layer of a stable hardly soluble or weakly dissociating chemical compound having a density close to that of the melt, which reduces the density differences between the particle and the melt at their interface.
The effect of barium titanate on the dielectric constant of a composite based on an epoxy press material
Authors: Eremin E N , Kukushina K G
Published: May 2021

The paper considers the effect of the introduction of barium titanate (BaTiO3) on the dielectric properties of a composite material based on an epoxy press material. The technology for preparing a composite material with a high dielectric constant is presented. The physicomechanical and dielectric properties of the composite are presented. The possibility of increasing the dielectric constant of the material is shown, as well as the technology of manufacturing the housing elements of spiral antennas. It was found that filling with 30 % of the BaTiO3 mass increases the dielectric constant by 1.5 times.
X-ray spectral analysis of surface structures formed on copper alloys during film fasting
Authors: Kubich V I , Cherneta O G , Yurov V M , Oleshko V S
Published: May 2021

The paper establishes the nature of the redistribution of chemical elements and their concentration in secondary surface structures for the material systems “steel 45XN2MFA-grease-BrOTsS4-4-2.5”, “steel 45XN2MFA-grease-BrOTsS4-4-4”, “steel 45XN2MFA-grease-L-63 ”, tested under the conditions of simulating film starvation when lubricated with 15W40 Lukoil-Super SAE SG/CD engine oil. Since the formula obtained by us includes the Gibbs energy, the self-organization of the structure under consideration naturally also enters. General laws of self-organization are observed when a number of conditions are met: irreversibility, openness (nonequilibrium), nonlinearity, instability (coherence), dissipativity. All these elements were observed and described by us in this work. It is due to self-organization that the distribution of chemical elements carbon and oxygen occurred on the surfaces L63 and BrOF4-4-4. To this effect must be added a decrease in the surface tension of the lubricant.
Analysis of the stress state of cylindrical workpieces during pipe end crimping with wall thinning
Authors: Larin S N , Larina M V , Nuzhdin G A
Published: May 2021

Workpices with different cross sections in the orthogonal direction along the height can be produced by crimping of hollow cylindrical blanks. This operation is highly productive and makes it possible to obtain various types of connectors. This article discusses simultaneous crimping and thinning of the workpiece wall at the exit from the deformation zone. During crimping, the thickness of the workpiece grows in the deformable part. In view of this, significant stresses may arise in the deformation zone. Therefore, selection of process parameters that provide the best stress state of the products is relevant. This article presents a study of the stress state in the combined process of crimping with wall thinning.
A study of dynamics of the operational performance of a single-bucket excavator, taking into account the operating time during construction of transport infrastructure of oil and gas facilities
Authors: Salikhov R F , Permyakov V B , Filippov Yu O , Grusnev M G
Published: May 2021

The paper presents the results of studies of the impact of operating time of single-bucket excavators on their operational performance. The results of production experiments made it possible to establish the dependence of the pressure change in the hydraulic system of the excavator during the process of cutting soil on the operating time. This parameter characterizes the variation value of the cutting resistance of soil at the cutting edge of a bucket, the duration of operation cycle and its operational productive capacity. Based on the results of the study, a technique has been developed that permits to determine economically feasible periods of effective operation of excavators, as well as to establish the optimal technological parameters for cutting soil: the thickness of the soil shavings and speed of its cutting by an excavator.
Angular displacement sensor based on oscillistor effect
Authors: Cheredov A I , Shchelkanov A V
Published: May 2021

The development of angular displacement sensors with a frequency output signal based on the oscillistor effect in electronic germanium is considered. The experimental results of the dependence the oscillistor oscillation frequency on angular displacement are described in the paper. Angular displacement sensors sensitivity is 1.0 kHz/deg at temperature of 295 K. With decreasing temperature the sensitivity increases and reaches 40 kHz/deg at 77 K. The design of the oscillistor-based sensor is presented.
Variable formation plasticity matrices of a three-dimensional body when implementing a step loading procedure
Authors: Klochkov Yu V , Nikolaev A P , Vakhnina O V , Sobolevskaya T A , Klochkov M Yu
Published: May 2021

Nowadays, the task of creating and improving computational algorithms for determining the stress-strain state (SSS) of technosphere objects and systems, taking into account the physically non-linear stage of operation of the material of structures and their elements, is quite relevant. A variational approach to the formation of a plasticity matrix at the loading step for a three-dimensional body is presented on the deformation theory of plasticity. A variant of obtaining the plasticity matrix using the operations of differentiating the covariant components of the stress tensor with respect to the covariant components of the strain tensor is considered. As an alternative to it, an option has been developed for the formation of a plasticity matrix at the loading step, based on the hypothesis of proportionality of the components of the deviator of stress increments to the components of the deviator of strain increments for three-dimensional bodies. The use of such option of forming a plasticity matrix at the loading step in software systems can significantly simplify the programming process and make it more understandable to potential users of computing systems in the design and reconstruction of technosphere objects and systems.
Study of the antivibration suspended seat oscillations with quasi-zero stiffness effect under sinusoidal excitation
Authors: Korytov M S , Shcherbakov V S , Titenko V V , Pochekueva I E
Published: May 2021

The relevant task of reducing the vibrations transmitted to a human operator of a construction or road vehicle during operating process is accomplished, among other things, by conducting the research on mathematical models. Oscillations simulation of the human operator’s seat antivibration suspension by means of the numerical solution of the ordinary differential equations system remains one of the main methods of the study, used in particular for the discrete mathematical models verification. Therefore, the problem of determining the rational value of the maximum integration step by using the numerical method in solving the systems of the ordinary differential equations describing the operator’s anti-vibration suspended seat oscillations is relevant. A discrete mathematical model of a human operator’s seat performing the forced vertical oscillations during kinematic excitation of base movements was developed through the use of the differential equation of the translational oscillations of mass on a movable base. The prescribed displacements of the seat base are described by the harmonic oscillation equation. The numerical solution of the ordinary differential equations system is carried out via the built-in ode45 function of the MATLAB mathematical modeling system. Moreover, the parameters of the developed mathematical model are described, the calculation scheme and an example of a static force characteristic including the quasi-zero stiffness region in the middle section of the characteristic are given. The determination accuracy of the maximum acceleration of the seat in the steady-state oscillation mode is shown to decrease when the value of the maximum allowable integration step increases. It is recommended to limit the value of the maximum allowable integration step to one hundredth of a second. Besides, the effect of the values duality of the maximum acceleration and maximum internal movement of the seat relative to its own base with small changes in the base displacement amplitude, which must be taken into account in modeling, is also revealed.
Stability investigation of a nonlinear hydraulic actuator in terms of wave processes
Authors: Syrkin V V , Galuza Y F , Kvasov I N , Abramova I A
Published: May 2021

In technological machines for various purposes, hydraulic actuators are widely used, which are constantly being improved in terms of the characteristics of power, speed and accuracy. These parameters must be stable, which requires making certain changes in the design of these actuators that allow them to withstand the operating modes of technological machines in the limits search. The authors consider results of the stability investigation of a nonlinear hydraulic actuator under the action of wave processes in its lines. They propose mathematical models of the wave process, which to some extent reflect its influence on the movement of the hydraulic motor in the form of a damping effect. For a nonlinear hydraulic actuator under the action of wave processes, a mathematical model and the results of the study of this hydraulic actuator are presented in the form of conditions, under which the stability of its operation is ensured.
Experimental study on seismic behavior of gangue concrete frame middle joints with different gangue aggregate replacement rates
Authors: Bai Guoliang , Gu Yu , Liu Hanqin
Published: May 2021

The low-cycled repeated loading experiment was carried out for gangue aggregate concrete middle joints with coal gangue aggregate replacement rates 0, 30%, 50%, 70%, 100%. The experiment was designed to investigate the joint failure modes, hysteretic characteristics, joint deformation and energy dissipation behavior of coal gangue aggregate concrete joints with different gangue aggregate replacement rates. Results show that the mechanical and failure process of coal gangue aggregate concrete frame joints, which is the same as that of normal concrete joint, may be composed of four stages: the initial cracking, the thorough cracking, the ultimate stage and the failure stage. It is found that the gangue concrete joints, with the increase of coal gangue aggregate replacement rate, are inferior to the normal concrete joint in the terms of hysteretic characteristics, joint deformation and energy dissipation behavior.