bluuebunny/crossref_metadata_2025 huggingface dataset:
Big Data and Artificial Intelligence: Opportunities and Threats in Electrophysiology
Authors: Leur Rutger R van de , Boonstra Machteld J , Bagheri Ayoub , Roudijk Rob W , Sammani Arjan , Taha Karim , Doevendans Pieter AFM , Harst Pim van der , Dam Peter M van , Hassink Rutger J , Es René van , Asselbergs Folkert W
Published: November 2020

The combination of big data and artificial intelligence (AI) is having an increasing impact on the field of electrophysiology. Algorithms are created to improve the automated diagnosis of clinical ECGs or ambulatory rhythm devices. Furthermore, the use of AI during invasive electrophysiological studies or combining several diagnostic modalities into AI algorithms to aid diagnostics are being investigated. However, the clinical performance and applicability of created algorithms are yet unknown. In this narrative review, opportunities and threats of AI in the field of electrophysiology are described, mainly focusing on ECGs. Current opportunities are discussed with their potential clinical benefits as well as the challenges. Challenges in data acquisition, model performance, (external) validity, clinical implementation, algorithm interpretation as well as the ethical aspects of AI research are discussed. This article aims to guide clinicians in the evaluation of new AI applications for electrophysiology before their clinical implementation.
Management of the process of formation and realization of competitive advantages of the Visegrad Four countries in the European market of ICT services
Authors: Krasnikova Nataliya O. , Dzyad Olena V. , Mihaylenko Olga G. , Hrechyn Kyrylo O.
Published: November 2020

Purpose – to assess the integration and management of the formation and implementation of the competitive advantages of the Visegrad Four countries in the European market of information, computer, telecommunication (ICT) services based on their analysis in the individual market segments.
Design/Method/Research approach - this study aims to determine the presence and nature of the competitive advantages of countries in the European ICT services market based on the calculation of export specialization indicators, to establish factors for their growth and effective implementation based on the results of structural, regressive, comparative analysis and synthesis.
Findings. It has been suggested that the introduction of the European rules for market organization stimulated the building-up in the Visegrad Four countries of their competitive advantages in the European ICT services market through innovative investment resources, effective management of private, public sector and international investors and personnel.
Practical implications. The accession of Eastern European countries to the European digital market and digital space requires a generalization of the experience of the Visegrad four countries and the identification of factors, directions and priorities of the national policy for the development of the ICT sector.
Originality/Value. Scientific novelty of the study - based on the calculation of the comparative advantage index, different integration and effectiveness of managing the competitive advantages of the Visegrad Four countries, primarily the sphere of IC services to the European market (relatively high - in the Czech Republic due to state financing, moderate – in Poland due to financial support from the state, in Slovakia due to private investment in R&D, low – in Hungary), this situation requires a balanced innovation and investment strategy of the countries in the future, the training of a sufficient number of qualified IT specialists, stimulation of private investment in R&D and business cooperation with the sphere of knowledge by means of tax and administrative incentives, facilitating the transition of small and medium-sized businesses on the principles of economics 4.0.
Paper type – empirical.
External environment transformation of Ukraine's tourist enterprises during the crisis
Authors: Bieloborodova Mariia , Bessonova Svitlana
Published: November 2020

Purpose – to identify trends in Ukraine's tourism enterprises' external environment to increase their competitiveness and stability in the relevant industry market.

Design/Method/Approach of the research. Theoretical generalization, method of abstraction, expert assessments, PEST-analysis, factor analysis, graphical method.

Findings. The research studies the changes in the external environment of tourist enterprises during the pandemic crisis. The critical factors of such enterprises' external environment are revealed based on considering their importance and the influence direction on the competitiveness of tourist business units. The paper covers the most significant negative and positive trends of changes in Ukraine's tourist enterprises' external environment. The authors provided recommendations for strategic planning of tourist business units' competitiveness.

Practical implications. The research results allow identifying areas for increasing the competitiveness of national tourism enterprises and effectively adapting to the external environment's transformations during the crisis in the globalized social and economic space.

Originality/Value. Based on the expert assessment, the authors proposed an expanded factors list of the external environment of national tourism enterprises, which, in contrast to the existing ones, consider the crisis's negative consequences. PEST-analysis clusters of environmental factors allowed to identify with a significant positive or negative impact on the competitiveness of tourism enterprises.

Research limitations/Future research. The research results provide a basis for further study of the external macro- and micro-environment of tourism enterprises at the local, regional, and national levels. And for element-by-element SWOT-analysis of tourism enterprises during the pandemic crisis.

Paper type – theoretical.
The development applied aspects of Ukraine’s tourist industry in the globalization conditions
Authors: Liutak Olena M. , Baula Olena V.
Published: November 2020

Purpose – to assess the tourism industry development and its impact on Ukraine’s economy, to identify a set of problems hindering the significant development of the tourism industry, and to justify ways to increase competitiveness in the world market.
Design/Method/Approach of the research. System approach, synthesis, analysis and comparison to assess the tourism development dynamics in Ukraine, correlation and regression analysis to determine the impact level of increasing the number of hotels and tourist-recreational enterprises on GDP growth in Ukraine, logical generalization to identify a set of problems holding back the significant development of local tourism and ways justification of increasing its competitiveness on the world market.
Findings. This article presents the results of assessing the tourism dynamics, particularly the tourist flows, the number of resorts, the number of tourists served by tour operators and travel agents. The authors substantiated the ways of increasing the local tourism sector's competitiveness.
Practical implications. The work results can make the basis for the development of fundamental and scientific-applied provisions contributing to the significant system formation of increasing the competitiveness of Ukraine's tourism industry by state and local authorities, establishing cooperation among market participants and forming optimal logistics flows, developing business models to optimize the flows of health and recreational facilities.
Originality/Value. The research value is that its applied scientific provisions can be implemented in the strategy of economic development of local tourism in analytical and mathematical justifications of the relationship between economic growth and tourism development, which ultimately increases Ukraine regions’ competitiveness for sustainable development of the country’s economy.
Research limitations/Future research. Future research should focus on identifying mechanisms to improve the procedure for increasing tourism enterprises' competitiveness and improving provided service quality.
Paper type –empirical.
OPTIMASI PEMBAGIAN BEBAN PADA TURBIN GAS BLOK 1 DAN BLOK 3 PLTGU PT. PJB UP GRESIK MENGGUNAKAN METODE ITERASI LAMBDA BERDASARKAN BASE POINT AND PARTICIPATION FACTORS
Authors: Risnawati Ery Fuji , Ulinnuha Nurissaidah
Published: November 2020

Pengoperasian sistem tenaga listrik yang baik dibutuhkan pada sistem pembangkitan untuk mendapatkan biaya operasi yang ekonomis dan pembagian beban yang optimal. Pengoptimalan pembangkitan dapat dilakukan dengan pembagian pembebanan atau economic dispatch untuk mendapatkan daya yang maksimum dengan biaya yang minimum. Metode yang dipakai yaitu iterasi lambda berdasarkan base point and participation factors untuk pembagian beban secara optimal. Pada penelitian ini, metode iterasi lambda berdasarkan base point and participation factors memberikan pembagian beban yang lebih optimal dan biaya operasi lebih hemat dibandingkan sebelumnya. Hasil pembagian beban pada kasus di PLTGU PT PJB UP Gresik yang lebih optimal yaitu turbin gas 1.3 pada Blok 1 dan turbin gas 3.3 pada Blok 3. Pada Blok 1, rata-rata daya yang dibangkitkan turbin gas 1.3 95,449 MW. Pada Blok 3, rata-rata daya yang mampu dibangkitkan turbin gas 3.3 89,205 MW. Biaya yang dihemat setelah optimasi diperoleh selisih pada Blok 1 sebesar Rp. 395.955.074,64 dan Blok 3 sebesar Rp. 565.297.532,00.
Spiritual Travel to Baitullah: Individual Piety in Global Capitalism
Authors: Basyah Dwi Santoso Ali , Qodir Zuly
Published: November 2020

The purpose of this paper explains critically related to one's journey to perform Hajj and Umrah (pilgrimage) concerning individual piety in the crowd (globalization and capitalization) of religious rituals. Hajj and Umrah are not only spiritual journeys that have personal ethical values. Hajj and Umrah can educate someone to be patient, calm, and more submissive to God. Hajj and Umrah also teach the perpetrators to be generous, have social sensitivity, and care with fellow human beings. The writing method in this paper is ethnographic-sociological. This paper's data is based on literature, observations, and interviews with pilgrims and Umrah from Indonesia in 2014 and 2018. This paper finds that the Hajj and Umrah are also closely related to the political economy problems administered by the state and the private sector, in addition to educating the perpetrators to be pious. Hajj and Umrah can thus be said to have two sides at once, namely individual piety and social class.
TO THE STATISTICAL ANALYSIS OF SOIL SHEAR TESTS RESULTS
Authors: Karaulov A. M , Korolev K. V , Bartolomey L. A , Bragar E. P
Published: November 2020

The result of any shear tests, which are the most popular laboratory methods for determination the strength characteristics of soils, is a set of values of the ultimate shear resistance and the corresponding normal pressure along the shear section. The theoretical background for the analysis of the soil shear tests results is the theory of probability and mathematical statistics. At the same time, we have questions about the determination of the calculation values of soil strength parameters. So, during the processing of shear tests results according to a consolidated-drained scheme for sandy soils the calculation values of soil specific cohesion are often negative, which is incorrect. The article considers an example of processing of shear tests data of sandy loam for various normal pressures, and analyzes the results of statistical processing of soil tests. The normative methods for probabilistic assessment of soil strength characteristics are based on using of normal distribution law of a random variable. It is assumed that the valuesof a random variable can vary from -¥ to +¥, while the soil strength parameters can vary in a limited range, i.e. accept only positive valuesfrom 0 to +¥. This circumstance does not matter for the majority of clayed soils, which strength parameters are far enough from zero. However, it has a significant effect on the result for small sought-for values, particularly, in assessing of specific cohesion for sandy soils. Therefore, for such cases, the article presents a variant of the statistical processing of the shear tests results with using the reduced normal distribution law of a random variable.
REMOTE CONTROL SYSTEM FOR TECHNOLOGICAL PARAMETERS OF PRESSED PILES
Authors: Gaido A. N , Pogoda A. G , Kolchedantsev L. M , Vershinin D. V
Published: November 2020

The article discusses the results of research in the field of developing a system that in real time allows you to display and remotely transmit the main technological parameters of indentation of factory-made piles (values of indentation forces, number and depth of immersed piles, their displacement relative to the design position). Unlike existing analogues, it allows you to additionally guide the installation of the indentation on the dive points of piles without instrumental removal of their position on the ground. This is done by orienting the installation through a global satellite navigation system. And the position of the piles is set automatically by calculating their coordinates obtained from the project in dfx format, previously entered into the memory of the on-board computer. The constituent elements of such a system are presented, as well as the interface for setting up and displaying technological parameters. The main technological indicators of the process in remote mode can be displayed on the display of any mobile device. It is shown that the cost of such a system is 8 % of the cost of the installation of the indentation of piles. It has been established that it pays off by reducing costs with the subsequent strengthening of grillage structures. These additional works are eliminated due to the prompt elimination of identified deviations, as well as improving the accuracy of installation of piles in the design position. The article presents an algorithm for performing work when setting up the system, receiving and transmitting relevant information. It is shown which participants at different stages will be involved in these processes. In conclusion, various performance indicators for the implementation of such a system are presented. Based on the results of the timing, it is proved that its use allows to reduce the duration and labor costs of both the production of works and the preparation of executive documentation. In addition, the information obtained can be integrated into the building information model, which will allow analyzing the operational reliability indicators of pile foundations.
MATURITY ANALYSIS OF BIM SOLUTIONS AS A TOOL FOR BUILDING LIFE CYCLE SUPPORT
Authors: Suntsov A. S , Simchenko O. L , Tolkachev Y. A , Chazov E. L , Samigullina D. R
Published: November 2020

In this article, by studying the market for BIM solutions, we analyze the capabilities of the building information model for its compliance with the modern BIM ideology. Development in the direction of supporting the process of building construction: from the moment of the idea of its construction to complete dismantling, the BIM concept also included economic and planned components. At the present stage, the information model should develop and live with the building, even after putting it into operation. The purpose of this study is to analyze the maturity level of BIM solutions in accordance with the current development of BIM technologies at all stages of the building's life cycle. The stages of creating a model are distinguished: drawing up technical specifications for designing, performing engineering surveys, compiling 3 types of information models in accordance with the requirements for the development of the relevant sections of project documentation. The stages of the BIM-model life cycle that need to be improved are identified: operation, dismantling of buildings. The features of compiling information models, existing BIM solutions from various software manufacturers are considered. The comparison of existing BIM-solutions at all stages of creating an information model. For the analysis of BIM solutions, an expert assessment method will be used. A list of indicators and their rating weight for the methodology of expert evaluations is compiled. An assessment of the maturity of BIM-solutions. As a result of the analysis, a graph was compiled that clearly demonstrates the degree of maturity of the information model for the life cycle. The average percentage of development as a result of the assessment is determined. Some BIM solutions raise the question of the appropriateness of their use in the field of BIM technologies.
About mixed forced, parametric and self-oscillations by limited excitation and delayed elasticity
Authors: Alifov A. A
Published: November 2020

Mixed forced, parametric, and self-oscillations are considered if there is a delay in the elastic force in the system. A dynamic model is a friction self-oscillation system describing the frictional self-oscillations that occur in many technical systems for various purposes (metal-cutting machines, textile equipment, brakes and a number of other engineering objects). The operation of the system is supported by the energy source of limited power. For the analysis we used the method of straight linearization which is easier than the known methods of analysis of nonlinear systems, has no time-consuming and complex approximations of different orders, provides an opportunity to obtain the final design ratios regardless of the specific type and degree of nonlinearity, thus reducing labor costs and time by several orders of magnitude. By using this method, we obtained solutions of a nonlinear system of differential equations describing the system's motion. The equations of non-stationary and stationary movements are derived. To analyze the stability of stationary movements, the stability conditions based on the Routh-Hurwitz criteria are compiled. Calculations were performed to obtain information about the effect of delay on the oscillation modes. It is shown that the delay affects both the magnitude of the amplitude and the location of the amplitude-frequency curve in the frequency range depending on the magnitude of the delay, the amplitude curve is shifted to the region of lower frequencies. The stability of stationary oscillations depends both on the energy source characteristics and lag value. The interaction of the oscillating system and the energy source leads to a number of effects, both in the presence and absence of the lag. However, their course may be different depending on the lag value.
Congo, de missie en de literatuur: Over David van Reybrouck, J. G. Schoup en Amaat Vyncke
Authors: Bel Jacqueline
Published: November 2020

Congo, the mission and the literature Missionaries played an important role in the colonisation of the Congo. They brought Christianity and “civilisation” to the new colony in central Africa, which was ruled over by the Belgian King Leopold II from 1885 to 1908 and by the Belgian government from 1908 to 1960. Missionaries were active in the field of education, but they also left their mark on colonial literature, both as authors and as protagonists. This article explores the traces of the missionaries in the literature on the Congo. Father Amaat Vyncke was an early example of a missionary and author, just as Father Garmijn and Father Constant de Deken. These missionaries provided a positive assessment on the colonial system in their writings. Writers like Ad. Verreet and J. G. Schoup used missionaries as protagonists in their novels. Schoup portrayed a sympathetic missionary who sharply criticised the colonial system. After the colonial period Jef Geeraerts painted a very negative image of the missionary in his Gangreen novels. However, the travel books written by Lieve Joris and Bart Castelein and the play Missie (Mission) written by David van Reybrouck (2007) sketched a positive and nostalgic image of the missionary.
Zen Communist: Breyten Breytenbach’s view from underground
Authors: Nash Andrew
Published: November 2020

In an interview after his release from prison, Breyten Breytenbach describes himself, at the time he became involved in underground politics, as a Zen Communist. He returns occasionally to this interaction of Marxist ideas of social revolution and Buddhist ideas of non-attachment, but never attempts to explain the resulting synthesis systematically. Indeed, for Breytenbach, being a Zen Communist is to resist systematic positions, to accept contradiction as a constant source of surprise and invention disruptive of all systematic thought. This paper examines how this interaction of Marxist and Buddhist ideas and practices has informed Breytenbach’s politics in three contexts: his initial exploration of a radical philosophy of history in his poetry (“Bruin reisbrief”, “Brown travel letter”); his role in the underground politics of Okhela in the 1970s; his reflections on politics and social change in his prison and prison-related writings. Key words: Zen communism, anti-apartheid movement, liberation, dialectic.
True Confessions, End Papers and the Dakar conference: A review of the political arguments
Authors: Giliomee Hermann
Published: November 2020

As a social critic Breyten Breytenbach published two books of political commentary and political analysis during the mid-1980s without the opportunity of engaging with commentators at home. While True Confessions of an Albino Terrorist is part autobiography and part searing comment on prison life, End Papers is a more detached dissection of the major political and cultural issues confronting South Africa. Breytenbach was now one of the respected international voices on the political crisis in South Africa. The violent break-up of apartheid had changed Breytenbach’s social criticism. In the place of the earlier rejection and denunciation had come a willingness to engage and reason with his audience. The Dakar conference of 1987, which Breytenbach co-organised, offered an ideal opportunity for this. The conference was given wide publicity and was seen by some as the catalyst that broke the ice for the negotiations between the government and the ANC two and a half years later.
Om tuis te gaan in styl: Territoriumskepping in Breyten Breytenbach se ’n Seisoen in die paradys (1976) en Dog Heart (1998)
Authors: Anker W. P. P.
Published: November 2020

This article is a study of how Breyten Breytenbach deals with the idea of home in his autobiographical prose, how he experiences home and how he constructs it. Although I hope that the argument will serve to give a new perspective on any of Breytenbach’s texts that deal with questions about the nature of home and the construction thereof, I only refer to ’n Seisoen in Paradys (A Season in Paradise, 1976) and Dog Heart (1998). The article uses concepts of Deleuze and Guattari to show how Breytenbach writes his home, and especially how his constructions of a home in his self-writings are products of a certain style of writing.
Epigenetically inactivated RASSF1A as a tumor biomarker
Authors: Raos Dora , Ulamec Monika , Katusic Bojanac Ana , Bulic-Jakus Floriana , Jezek Davor , Sincic Nino
Published: November 2020

RASSF1A represents one of the eight isoforms of the RASSF1 gene. RASSF1A is a tumor suppressor gene whose inactivation influences tumor initiation and development. In cancer, RASSF1A is frequently inactivated by mutations, loss of heterozygosity and, most commonly, by promoter hypermethylation. As epigenetic inactivation of RASSF1A was detected in various cancer types, it was extensively investigated and nowadays, the research on RASSF1A promoter methylation proceeds in the light of an epigenetic tumor biomarker. Analyses of DNA methylation of genes involved in carcinogenesis such as RASSF1A are currently done mostly on genomic DNA (gDNA). Simultaneously, cell-free DNA (cfDNA) from liquid biopsies has lately been developed as an early cancer diagnostic tool.  This review discusses the evidence on aberrantly methylated RASSF1A in gDNA and cfDNA from different cancer types and its utility for early cancer diagnosis, prognosis, and surveillance. Furthermore, methylation frequencies of RASSF1A in gDNA and cfDNA were compared in various cancer types. The weaknesses and strengths of the investigations mentioned above are discussed. In conclusion, although the importance of RASSSF1A methylation in relation to cancer was established, and it became included in several diagnostic panels, the evidence of its diagnostic utility is still experimental and not yet implemented in standard clinical health care.
THE IMPACT OF SPANISH INQUISITION ON ISLAMIC CIVILIZATION
Authors: ARSHAD RASYIDAH , ZAHRIN SYAIDATUN NAZIRAH ABU , SAMAD NURUL SHAHIRAH ABDUL
Published: November 2020

The Spanish Inquisition was established as an official body blessed by the Roman Catholic Church, because the Catholic rulers Isabella and Ferdinand were determined to rid Spain of any heretics or non-Catholics. The greatest impact of the inquisition was the banishment of Islam from Spain. Spain has been a vibrant civilization for six centuries, serving as the shield of other religions. There was no divine guidance left untouched, or even a small group of believers left. It has resulted in Islam being delayed in Christian Europe for several decades. Even though Muslims have come to Europe in the last two centuries, Islam has been practiced as a personal religion of worship and prayer, but never as a government that has protected and enriched the lives of all religions, as we have seen during the Muslim rule of Andalusia. The aim of this paper is specifically to discuss the policies of the Spanish Inquisition on the Muslims in Andalusia. Muslim policies are discussed in great depth compared to other groups, because they were the majority and most resistant to policies. The analysis of the impact of the Inquisition is important to understand how Islam was eradicated from the Spanish society and later re-emerged as a significant presence in Spain.
Material constitution of gem-quality ammonites – by-product of mining in the Saratov Region
Authors:   Sergo Ordzhonikidze Russian State Geological Prospecting University, Moscow, Russia, Petrochenkov D. A.
Published: November 2020

Manufactured articles of ammonites have been in increasingly higher demand in the recent decades. Ammonites have appeal for the unique shapes, color and age. The top suppliers of ammonites to the world market are Madagascar, Morocco, Canada and Russia. In Russia, gem-quality ammonites occur in the Saratov Region, apart from other places. The regional open pit mine at the settlement Dubki situated 7.5 km northeastward of Saratov supplies ammonites both to the Russian and global markets. The submicroscopic and electron microprobe analyses presented details of mineral composition and structure of ammonite shells. The test shell fragments included walls and partitions with layers of pyrite. The pyrite layers lay symmetrically relative to the partitions and inside walls of ammonite, and feature pronounced structural zonality. The partitions and walls are adjoined with narrow zones of fine-crystal pyrite. Then, a zone of coarse-crystal pyrite lies, with fragments of colloform pyrite. The gem-quality ammonites have mostly pyrites in their composition (to 96 % by mass) and are connected with the Upper Jurassic deposits. Among other things, ammonites contain aragonite, calcite, apatite, jarosite, gypsum, ferrian carbonate and organic substance. The original aragonite is preserved in walls and partitions of shells. Morphologically, the large prismatic, fine-crystal, colloform and globular species of pyrite are distinguished. Pyrite is actively decomposed by bacteria. The Saratov Region ammonites possess high decorative and processing properties, can be widely used in manufacturing of jewelry and are by-produced in the course of large-scale mining.
Cemented backfill with low-grade natural sand
Authors:   Belgorod State University, Belgorod, Russia, Rubashkina T. I. , Korneichuk M. A. ,   Belgorod State University, Belgorod, Russia
Published: November 2020

The subject of this research is cemented backfill mixtures made using fine and very fine natural sand with increased content of clay and flour particles. Aimed to study optimizability of grain size composition of low-grade fine and very fine natural sand, the physical and mechanical properties of sands from Bolshie Mayachki deposit in the Belgorod Region and blast-furnace granulated slag from metallurgical processing at Severstal were analyzed. Optimization of granular composition included enlargement of size modulus, reduction of specific surface of grains and decrease in the content of clay and flour particles. Initial sand was brought to standard quality level by introduction of slag sand (fractions of 0-5 mm). Then, the grain composition, particle size modulus, clay and dust-like particles content and specific surface area of each composite aggregate grain were determined using the methods described in the article. According to the test results, the increase in the proportion of slag in the composite aggregate leads to the decrease in the water demand due to enlargement of particles and lower content of clay components, which makes it possible to obtain compositions for cemented backfill with strength of 1–10 MPa at the reduced consumption of cement (by 7% on average) and with the preserved rheological characteristics.
Magnetic properties of natural weakly magnetic iron oxides of the Kursk Magnetic Anomaly
Authors:   Belgorod State National Research University (Belgorod, Russia), Gzogyan T. N. , Gzogyan S. R. ,   Belgorod State National Research University (Belgorod, Russia)
Published: November 2020

This paper contains the results of complex studies on magnetic characteristics of a system of basic natural weakly magnetic iron oxides isolated from the oxidized ferruginous quartzites of the KMA. It has been shown that their magnetic characteristics vary over a wide range and substantially depend on the nature of the samples, i.e. represent not only physical, but also genetic characteristics. The contrast in magnetic properties inside the system exceeds the mere hydroxides/quartz contrast; therefore, it is necessary to differentiate the recovery conditions for various iron oxides. For example, the magnetic characteristics of martite and hematite behave differently in different size classes. This dependence is most noteworthy for hematite. It has been shown that, despite the relatively low mass fraction of the ferromagnet, magnetic susceptibility of natural systems of weakly magnetic iron oxides may be an important genetic and diagnostic trait, which must be taken into account when designing all respective separation technology and equipment. The problem under consideration is directly related to mineral processing and the technology must ensure the recovery of both coarse and fine highly and medium magnetic particles into the concentrate.
Laser-photometric lump separation of gold-bearing ore
Authors:   All-Russian Scientific-Research Institute of Mineral Resources named after N. M. Fedorovsky (Moscow, Russia), Rassulov V. A. , Nerushchenko E. V. ,   Research and Production Enterprise GeoTestService (Moscow, Russia)
Published: November 2020

This paper establishes the conditions for selecting the optimal lump separation method based on the values of indicator properties of the ore minerals and demonstrates respective pilot testing results for low-grade quartz-type sulfide gold-bearing ores. The studies have shown the high efficiency of laser-photometric processing of ores with low contents of finely disseminated ore components, for which other methods are ineffective. On the example of ore from the Natalka deposit, it has been shown that acceptable lump separation performance requires division of the original ore into high-grade balance ore (the separation of which would be impractical), low-grade balance ore (to be subjected to lump separation), and an off-balance mineralized mass. Lump processing remains efficient up to ore temperatures of minus 15 °C, if rinsed with 4 °C water. The following concentration indicators were achieved for the lean ore of the process sample taken from the Alternativny section at ore temperatures above minus 15 °С: with the concentrate yield of 20 to 28 %, the gold content increases by 3.0–4.5, with an average level of metal losses in the tailings of approximately 13 %. At ore temperatures down to minus 21 °C, when an opaque ice film with the thickness of over 1 mm is formed on the lump during its screening with washing, metal losses in the separation tailings become 2.0–2.5 times higher. The authors are grateful to the employees of TOMRA, CC of CJSC Polyus Zoloto, Natalka FMS department of OJSC RiM, and FSBI VIMS, who assisted in the pre-concentration technology testing for the ore of the Natalka deposit.
Pit sump drainage thickening to remove saponite rock suspension
Authors:   Saint Petersburg Mining University (St. Petersburg, Russia), Alexeev A. I. , Zubkova O. S. ,   Saint Petersburg Mining University (St. Petersburg, Russia), Vasilyev V. V. ,   Saint Petersburg Mining University (St. Petersburg, Russia), Kurtenkov R. V. ,   Saint Petersburg Mining University (St. Petersburg, Russia)
Published: November 2020

Advanced water supply systems for industrial enterprises represent complex facilities that include the supply of fresh water and its preparation for the process, treatment, decontamination and disposal of waste water, disposal of the resulting residue, and often the organization of a closed water cycle. Designing and operating such facilities is a complex technical and environmental task, which must be solved using the best available technologies. The management system for the drainage waters generated in diamond mining at the Lomonosov GOK of PJSC Severalmaz in the Arkhangelsk Region is a typical example. The precipitation indicators for the suspension in the drainage water were established using the traditional coagulants of aluminum sulfate and hydroxochloride, as well as an experimental sample of a calcium-aluminosilicate inorganic precipitator. The results of experiments with different coagulant dosages were used to establish the average and effective precipitation rate, the residual aluminum content in the water, acidity and turbidity of the clarified drainage water. The results obtained allow substantiating the higher efficiency of the experimental coagulant in terms of the water clarification rate and the possibility of meeting the sanitary standards for water discharge into natural water bodies envisaged by SanPiN 2.1.5.980-00. The work was carried out with the financial support of the Russian Science Foundation under Agreement No. 18-19-00577 dated April 26, 2018, on the provision of a grant for fundamental and exploratory research.
Establishing the causes for low operational reliability of slurry pumps based on a system analysis
Authors:   Mining Institute, M. K. Ammosov North-Eastern Federal University (Yakutsk, Russia), Ovchinnikov N. P.
Published: November 2020

In practice, the difference between the actual and planned costs forthe maintenance of slurry pumps used at concentration and screening plants of Russian diamond mining companies is mainly represented by the costs of purchase and delivery of their new original (OEM) parts. These costs are primarily due to the premature failure of pump components. The impeller is the least reliable or fail-proof element in their design. The main cause for impeller failure is the intense abrasion of its surfaces by mechanical impurities contained in the slurry pumped. The respective comprehensive scientific research has established the critical factors affecting the weighted average service life of pump impellers used by Russian diamond mining companies. A linear regression model has also been designed, allowing to predict the service life of impellers in Russian-made slurry pumps for the processing plants of PJSC ALROSA with a high degree of probability, duly confirmed using the Fisher criterion. The results obtained are of great practical interest as they make it possible to further assess impeller operational durability and to accordingly predict the maintenance costs for the slurry pumps, depending on their specific operation conditions at Russian diamond mining companies.
Comparison of coking additives obtained from different types of oil stock
Authors:   KINEF LLC, Kirishi, Leningrad Region, Russia, Kameshkov A. V. ,   Saint Petersburg Mining University, Staint Petersburg, Russia, Kondrasheva N. K. ,   Saint Petersburg Mining University, Staint Petersburg, Russia, Gabdulkhakov R. R. ,   Saint Petersburg Mining University, Staint Petersburg, Russia, Rudko V. A. ,   Saint Petersburg Mining University, Staint Petersburg, Russia
Published: November 2020

Coke producers often face a shortage of valuable grades of coals, i.e. coking coals. This paper examines the possibility to obtain a coking additive by applying delayed coking to various types of heavy petroleum residues. The paper also gives a comparative description. Five types of heavy petroleum residue from the KINEF oil refinery were used in the experiments that aimed to produce carbon material. They included vacuum residue ELOU-AVT-6, vacuum residue S-1000 resultant from the hydrocracking process, visbreaker bottoms from the S-3000 unit, and two mixtures of the ELOU-AVT-6 unit products: a mixture of vacuum residue and third vacuum cut; and a mixture of vacuum residue, third vacuum cut and atmospheric residue. The carbon material obtained from all the above types of raw materials was analyzed for quality; an X-ray diffraction analysis was carried out; and the interplanar spacings d002 and d110 were calculated, as well as the linear sizes of Lc and La crystallites. The coking additive obtained instead of the typical petroleum coke was found to meet the specification. Thus, the volatile matter content in it is within the range from 15 to 25 wt%. This additive can be used in steel production instead of coking coal. The coking additive from a mixture of vacuum residue, third vacuum cut and atmospheric residue has the highest content of volatile matter (19.30%), while the coking additive from the visbreaking residue from the S-3000 has the lowest volatile matter content (16.15%). The latter is due to the fact that the primary petroleum material was subjected to light thermal cracking. It is shown that as the composition of the heavy petroleum residue changes, so do the properties of the resultant coking additive: a higher fraction of the low-boiling components in the feedstock is associated with a higher volatile matter content; the carbon materials produced from vacuum residue have a higher microhardness; the coking product produced from the visbreaker bottoms has a lower porosity compared with the product obtained from the vacuum residue. This research was carried out as part of a governmental assignment of the Ministry of Education and Science of the Russian Federation in the framework of the following research project: 0792-2020-0010 “Fundamentals of innovative processing techniques to obtain environmentally-friendly motor fuels and innovative carbon materials with variable macro- and microstructure of the mesophase from heavy hydrocarbon materials”. The research was carried out at the laboratory of the Shared Knowledge Centre of the Saint Petersburg Mining University.
Electrolytic production of aluminium. Review. Part 2. Development prospects
Authors:   EKSPERT-AL LLC, Saint Petersburg, Russia, Gorlanov E. S. , Kawalla R. ,   Freiberg Mining Academy, Freiberg, Germany, Polyakov A. A. ,   Saint Petersburg Mining University, Saint Petersburg, Russia
Published: November 2020

This paper looks at the evolution and the current status of inert electrodes. It also describes attempts to design new-generation aluminium cells with wettable cathodes and vertical electrodes. Numerous laboratory studies and pilot tests demonstrate that aluminium cells equipped with inert electrodes are environmentally safe and can deliver a breakthrough technology enabling to bring the power consumption down below 10 kWt·h/kg Al and at the same time increase the production even in the limited capacity of the electrolytic bath. There exists a number of projects aimed at commercializing the inert electrode technology. And despite the apparent loss of interest in this technology on the part of researchers and aluminium producers, relevant pilot tests are scheduled for 2024. A number of alternative innovative power saving cryolite-alumina bath techniques are being discussed, which should allow to get close to the theoretical level of power consumption and provide a dramatic boost in the cell capacity. The paper examines potential application of thermoelectric generators to reduce heat losses, the use of minimum anode-to-cathode distance and vertical nonwettable electrodes, and a transition to 3D electrodeposition of aluminium with cathode polarization.
Electrochemical Deposition of CoNiFe Alloy from Concentrated Chloride Electrolyte
Authors:   Scientific-Manufacturing Complex Technological Centre, Moscow, Zelenograd, 124498, Russian Federation, Tikhonov R.D.
Published: November 2020

Heating the chloride electrolyte to a temperature of 70 °C at the concentration ratio of CCo:CNi:CFe 1:1:1 provides stabilization of electrochemical deposition of the CoNiFe alloy components as a result of discharge of metal ions (Fe2+ Cl- )+ , (Со2+ Cl- )+ , (Ni2+ Cl- )+. Electrolyte filtering and correcting pH with HCl provides a reproducible deposition of CoNiFe films. Based on the experimental results of the CoNiFe films, a mechanism of electrochemical deposition is proposed, which differs in view of the phenomena occurring in the volume of electrolyte: mass draft ions, with the determining effect of mobility and the formation of positive ions on the anode. CoNiFe films are produced without mechanical stresses, with a uniform structure and with high magnetic parameters without high heat firing.
Electrophysical Characteristics of Tantalum Oxide Structures
Authors:   National Research University MIET, Zelenograd, Russian, Belov V.S. ,   Institute of Nanotechnology of Microelectronics of the Russian Academy of Sciences (INME RAS), Moscow, Russian Federation
Published: November 2020

In this work has been developed a technology for obtaining nickel-insulator-aluminum structure with 7 nm thick tantalum oxide deposited by atomic-layer deposition. An asymmetric current-voltage characteristic of the structure is obtained, and the heights of potential barriers at the metal-insulator interface are determined. The permittivity of the tantalum oxide film has been determined experimentally in this work.
Appearance of Intrinsic Magnetization in FeMn Antiferromagnetic Film under the Action of Spin-Polarized Current
Authors:   A. I. Shokin ISTOK Research and Production Enterprise, Fryazino, Moscow oblast, 141190 Russian Federation, Panas A.I. , Chigarev S.G. ,   Kotel’nikov Institute of Radio Engineering and Electronics (Fryazino Branch), Russian Academy of Sciences, Fryazino, Moscow oblast, 141190 Russian Federation, Vilkov E.A. ,   Kotel’nikov Institute of Radio Engineering and Electronics (Fryazino Branch), Russian Academy of Sciences, Fryazino, Moscow oblast, 141190 Russian Federation, Byshevski-Konopko O.A. ,   Kotel’nikov Institute of Radio Engineering and Electronics (Fryazino Branch), Russian Academy of Sciences, Fryazino, Moscow oblast, 141190 Russian Federation
Published: November 2020

The article presents the results of research of two spin-injection sources of THz radiation using different structures of thin-film magnetic transitions (MT) with antiferromagnetic (AFM) FeMn film of nanoscale thickness and ferromagnetic (FM) Fe layer. In both variants, the possibility of intrinsic magnetization forming in the AFM film under the action of a spin-polarized current of a relatively small value formed in the FM layer is shown. The physical foundations of this effect based on the AFM sublattices beveling by a spin-polarized current due to the sd-exchange interaction of the conduction electrons spins with the spins of d electrons of the FM crystal lattice are considered. This does not require an external magnetic field. sd-exchange mechanism of excitation of intrinsic magnetization in AFM is an alternative to the spin-orbit mechanism, which has been widely considered recently. The relations for calculating the frequency and power of spin-injection radiation are given. New experimental results have been obtained that develop the concept of the AFM's intrinsic magnetization. The non-thermal nature of spin-injection radiation and the possibility of increasing the efficiency of the emitter operation due to the ordering of the MT structure by an external magnetic field are shown. The way of increasing the efficiency of spin-injection emitters by creating structures with multiple independently operating micro-emitters at frequencies close to 16 THz and with a signal power of up to a hundred microwatts has been determined. In general, it is shown that the use of the effect of excitation of intrinsic magnetization in AFM is of interest, both from the point of view of the development of theoretical ideas about the magnetic properties of AFM, and from a practical point of view for the creation of spin-injection lasers (tasers).
THE PERIOD OF PORTO FRANCO AT DELOS
Authors: Kukoba Liena
Published: November 2020

The article deals with the features and changes in the development of Delian polis during the free port period. The economic development was analized, it has experienced the highest prosperity due to duty-free trade and the slave market on the island. The political evolution of Delos from the classical polis to the Hellenistic city is characterized. The peculiarities of religious life on the island, which combined both Greek and Eastern cults, were identified.
NTERETHNIC RELATIONS BETWEEN SLAVS AND IRANIANS AS A BASIS FOR THE TRADITIONAL SPIRITUAL CULTURE OF UKRAINIANS
Authors: Sereda Maksym
Published: November 2020

The article deals with the manifestations of ethno-cultural interaction of the Slavs with their neighbors, nomadic Iranian ethnic groups. The result of their communication was the emergence of a number of mythological images of Iranian origin in the Slavic and, in particular, Ukrainian culture. This is the famous Viy mentioned in the story by Mykola Gogol, the ancient gods Khors and Semargl, the cult of fire. New studies by linguists, literary critics, and folklorists allow us to take a different look at the previously proposed etymologies and reinforce them.
Оптико-механические средства воспроизведения действительности как конкуренты традиционного искусства
Authors: Севастьянов Александр Никитич
Published: November 2020

В статье отмечается, что к решающему перевороту искусство влекли не только психологические и идейные, но и обусловленные прогрессом науки и техники обстоятельства. Показано, как технологии физионотраса, дагеротипа и фотографии изменили художественные средства отражения действительности.