bluuebunny/crossref_metadata_2025 huggingface dataset:
SELECTION OF THE LAYOUT OF THE MAIN SYSTEMS OF A HEAVY MULTICOPTER TAKING INTO ACCOUNT THE REQUIREMENTS OF AVIATION REGULATION
Authors:   Moscow Aviation Institute (National Research University), Trofimov Aleksey , Postnikov Sergej ,   Moscow Aviation Institute (National Research University)
Published: April 2021

This article discusses the possibility of using a multicopter type aircraft as a transport vehicle in urban environments. This type of transport is the most promising in the near future, given the constantly growing number of traffic jams in large cities. The assessment of this aircraft is presented, taking into account the reliability requirements specified in the regulatory documents. The analysis of the aviation regulations requirements in terms of the aircraft systems reliability was carried out. Also the paper presents six options for the multicopter layout with a different number of propellers, taking into account the propeller control system, power supply system and control system. Other onboard systems are not considered, since their failures do not lead to an aircraft crash. An assessment of these options, taking into account the multicopter most critical onboard equipment layout according to reliability criterion by budgeting the requirements for one thrust generation channel, is given. Fault trees and failure situations that lead to a disastrous situation are also presented for each multicopter layout separately, as well as proposals for the number of independent channels for the power supply system and control system. Based on the set quantitative requirements for the occurrence of a catastrophic situation for the main on-board equipment and various layout options, taking into account the number of propellers and proposals for their architecture, power supply systems and control systems the most promising multicopter architecture options are determined. They meet the requirements for failure safety for a catastrophic situation.
INFLUENCE OF HEATING OF A GAS-AIR MIXTURE ON THE CHARACTERISTICS OF COMBUSTION OF FUEL GASES
Authors:   Perm National Research Polytechnic University, Shilova Alyona , Bachev Nikolay ,   Perm National Research Polytechnic University, Bulbovich Roman ,   Perm National Research Polytechnic University
Published: April 2021

For a stable position of the flame front in the combustion chambers of gas turbine power plants, the fresh gas-air mixture must be heated to the ignition temperature during the entire operation process. With air excess coefficients in the interval between the upper and lower concentration limits, reverse currents from the zone of developed combustion successfully cope with this task. When organizing low-temperature combustion near the lean limit, the contribution of reverse currents to heating the fresh gas-air mixture turns out to be insufficient and additional external heating of the components in special heaters with exhaust gases from the turbine is required. The temperature characteristics of the fresh gas-air mixture at the inlet to the chamber and in the zone of return currents, as well as combustion products in the developed flame zone, were obtained from the solution of the energy balance equations. The modes of low-temperature lean combustion with excess air coefficients exceeding the lower concentration limit α = 2 are considered. The calculations were carried out for two values of the ejection coefficient in the zone of reverse currents K = 0.14 and K = 0.30. A K value of 0.14 was obtained using empirical relationships. The value K = 0.30 was obtained from the condition that during stoichiometric combustion, the gas-air mixture is heated completely by reverse currents. It is shown that with an increase in the excess air ratio to ensure a stable position of the flame front, the role of external heating of components increases.
NUMERICAL STUDY OF DYNAMICS INTRACHAMBER PROCESSES IN SOLID PROPELLANT SUSTAINER TAKING INTO ACCOUNT FLIGHT OVERLOADS. PART 2. CALCULATION RESULTS
Authors:   Perm National Research Polytechnic University, Egorov Mikhail , Egorov Dmitry ,   JSC "Scientific-Research Institute of Polymeric Materials", Egorov Sergey ,   JSC "Scientific-Research Institute of Polymeric Materials"
Published: April 2021

The article presents the results of numerical calculations of the dynamics of in-chamber processes in the cruise missile's second-stage cruise missile propulsion system, taking into account the distributed space-three-dimensional and time-varying flight overloads, obtained using the previously developed calculation method and the application software package created on its basis. The value of the flight overload of a cruise missile, in projections along the coordinate axes, is determined depending on the mass, speed and trajectory of the rocket, mass flow and thrust of the rocket engine. The external aerodynamic effect on the in-chamber process in the SRM is neglected. The results of the calculations are given in comparison-without taking into account and taking into account the effect of flight overload. Two main stages of the rocket engine operation are considered: entering the operating mode and the main operating mode. At the stage of entering the SRM operation mode, the overload affects the redistribution of the temperature of the gas phase of the combustion products in the area of the front bottom of the combustion chamber. On the March operation of the SRB as a result of the flight of an overload, an increase of the particle density (liquid drops) small and large diameter of the solid phase of the combustion products in the wall of the back plate and pre-exhaust gas flue, and the degree of change in the distribution density of the particles (liquid droplets) that are larger than large. The results of the numerical study are in good agreement with the experimental data – the results of bench tests of the rocket engine and the results of flight tests of the cruise missile, which includes the considered SRM.
ENSINO REMOTO PARA ESTUDANTES DO PÚBLICO-ALVO DA EDUCAÇÃO ESPECIAL NOS INSTITUTOS FEDERAIS
Authors: Bueno Melina Brandt , Leite Graciliana Garcia , Vilaronga Carla Ariela Rios , Mendes Enicéia Gonçalves
Published: April 2021

Em decorrência da pandemia da Covid-19 e das medidas de distanciamento social requeridas, as aulas presenciais foram suspensas no início de 2020, e o objetivo do estudo consistiu em analisar como ficou o ensino para os estudantes público-alvo da educação especial (PAEE) nos Institutos Federais de Educação, Ciência e Tecnologia (IFs), neste cenário. A abordagem exploratória e descritiva, do tipo pesquisa de levantamento, foi realizada junto 168 docentes de diferentes campi dos IFs. A coleta de dados foi realizada por meio de questionário (Google Forms). Os dados obtidos foram sistematizados, organizados e analisados quantitativa e qualitativamente em categorias temáticas, acompanhando as variáveis do instrumento. Os resultados evidenciaram que os docentes buscaram diferentes alternativas no ensino remoto, tais como planejar colaborativamente; adotar procedimentos diferenciados no planejamento específico; prever modificações na prática pedagógica; utilizar material didático e avaliações adaptadas etc. As tecnologias e o ambiente virtual foram considerados tanto em aspectos positivos quanto desafiadores. Conclui-se que a demanda para atender às necessidades educacionais dos estudantes PAEE no ensino remoto exigiu o replanejamento dos processos pedagógicos, com diferentes ações, que variaram a depender de cada instituto. Contudo, faltaram diretrizes para elaborar o plano de ensino individualizado, assim como maior articulação com professores de educação especial, o que pode impactar na qualidade do ensino e aprendizagem do PAEE. Sugere-se que outras pesquisas sejam desenvolvidas, buscando maior aprofundamento e a avaliação das experiências docentes durante o ensino remoto no contexto da pandemia.
MADRaS : Multi Agent Driving Simulator
Authors: Santara Anirban , Rudra Sohan , Buridi Sree Aditya , Kaushik Meha , Naik Abhishek , Kaul Bharat , Ravindran Balaraman
Published: April 2021

Autonomous driving has emerged as one of the most active areas of research as it has the promise of making transportation safer and more efficient than ever before. Most real-world autonomous driving pipelines perform perception, motion planning and action in a loop. In this work we present MADRaS, an open-source multi-agent driving simulator for use in the design and evaluation of motion planning algorithms for autonomous driving. Given a start and a goal state, the task of motion planning is to solve for a sequence of position, orientation and speed values in order to navigate between the states while adhering to safety constraints. These constraints often involve the behaviors of other agents in the environment. MADRaS provides a platform for constructing a wide variety of highway and track driving scenarios where multiple driving agents can be trained for motion planning tasks using reinforcement learning and other machine learning algorithms. MADRaS is built on TORCS, an open-source car-racing simulator. TORCS offers a variety of cars with different dynamic properties and driving tracks with different geometries and surface.  MADRaS inherits these functionalities from TORCS and introduces support for multi-agent training, inter-vehicular communication, noisy observations, stochastic actions, and custom traffic cars whose behaviors can be programmed to simulate challenging traffic conditions encountered in the real world. MADRaS can be used to create driving tasks whose complexities can be tuned along eight axes in well-defined steps. This makes it particularly suited for curriculum and continual learning. MADRaS is lightweight and it provides a convenient OpenAI Gym interface for independent control of each car. Apart from the primitive steering-acceleration-brake control mode of TORCS, MADRaS offers a hierarchical track-position – speed control mode that can potentially be used to achieve better generalization. MADRaS uses a UDP based client server model where the simulation engine is the server and each client is a driving agent. MADRaS uses multiprocessing to run each agent as a parallel process for efficiency and integrates well with popular reinforcement learning libraries like RLLib. We show experiments on single and multi-agent reinforcement learning with and without curriculum
Effects of Knowledge and Reflection in Intrapersonal Deliberation
Authors: Yang Tian , Wang Yang , Zhang Weiyu
Published: April 2021

Deliberation is not a black box. In this paper, we look at intrapersonal deliberation, a process different from interpersonal deliberation. In particular, we examine two variables, i.e. knowledge access and reflection, looking at their effects on attitudes, attitude certainty, and willingness to express opinions. A between-subjects 2×2 factorial experimental study (N = 83) shows that both knowledge access and reflection could serve as 'double-edged swords' in deliberation. Knowledge access changed attitudes towards a milder position while reduced willingness to express opinions in public. Meanwhile, reflection increased perceived attitude correctness, which might have a mixed implication for deliberation. Further theoretical and practical implications are discussed.
Developments in the Credit Score Distribution over 2020
Authors: Goodman Sarena , Li Geng , Mezza Alvaro , Nathe Lucas
Published: April 2021

The distribution of household credit risk can vary with aggregate economic and credit conditions. For example, the share of subprime-scored borrowers declined at a relatively steady pace during the economic recovery from the Global Financial Crisis. Although the COVID-19 pandemic interrupted the economic conditions that supported this trend, the pace of decline accelerated following the pandemic’s onset in March 2020. The analysis that follows suggests that this acceleration was largely driven by the Coronavirus Aid, Relief, and Economic Security Act’s (CARES Act) forbearance provisions.
Limited Participation in Equity Markets and Business Cycles
Authors: Morelli Juan M.
Published: April 2021

This paper studies how the rise in US households' participation in equity markets affects the transmission of macroeconomic shocks to the economy. I embed limited participation into a New Keynesian framework for the US economy to analyze the individual and aggregate effects of higher participation. I derive three main results. First, participants are relatively more responsive to shocks than nonparticipants. Second, higher participation reduces the effectiveness of monetary policy. Third, with higher participation the economy becomes less volatile. I contrast key predictions of my model with new micro-level empirical evidence on the response of consumption to monetary policy shocks.
Unintended Consequences of Unemployment Insurance Benefits: The Role of Banks
Authors: Arslan Yavuz , Degerli Ahmet , Kabaş Gazi
Published: April 2021

We use disaggregated U.S. data and a border discontinuity design to show that more generous unemployment insurance (UI) policies lower bank deposits. We test several channels that could explain this decline and find evidence consistent with households lowering their precautionary savings. Since deposits are the largest and most stable source of funding for banks, the decrease in deposits affects bank lending. Banks that raise deposits in states with generous UI policies squeeze their small business lending. Furthermore, counties that are served by these banks experience a higher unemployment rate and lower wage growth.
Price Setting and Volatility: Evidence from Oil Price Volatility Shocks
Authors: Klepacz Matthew
Published: April 2021

How do changes in aggregate volatility alter the impulse response of output to monetary policy? To analyze this question, I study whether individual prices in Producer Price Index micro data are more likely to change and to move in the same direction when aggregate volatility is high, which would increase aggregate price exibility and reduce the effectiveness of monetary policy. Taking advantage of plausibly exogenous oil price volatility shocks and heterogeneity in oil usage across industries, I find that price changes are more dispersed and less frequent, implying that prices are less likely to move in the same direction when aggregate volatility is high. This contrasts with findings in the literature about idiosyncratic volatility. I use a state-dependent pricing model to interpret my findings. Random menu costs are necessary for the model to match the positive empirical relationship between oil price volatility and price change dispersion. This is the case because random menu costs reduce the extent to which firms with prices far from their optimum all act in a coordinated fashion when volatility increases. The model implies that increases in aggregate volatility do not substantially reduce the ability of monetary policy to stimulate output.
Can CHIRPS fill the gap left by the decline in the availability of rainfall stations in Southern Africa?
Authors: WV Pitman  , AK Bailey
Published: April 2021

Rainfall is the most important input to any hydrological or water resources study. The decline in the number of suitable rainfall stations since the 1970s is a cause for concern, plus there is an additional complication in that – for a number of catchments – mean annual precipitation (MAP), as derived from a recent study by Pegram, differs substantially from those adopted by the Water Resources of South Africa, 2012 study (WR2012) (mostly as derived by Dent). Rainfall data sourced by the Climate Hazards Group InfraRed Precipitation with Station data (CHIRPS) satellite database was selected as a basis for comparison, both for catchment MAP and time series of monthly rainfall as used for input to the Pitman hydrological model (WRSM/Pitman, previously called WRSM2000). The analyses revealed that the WR2012 method of constructing the time series yielded the best results overall, but the difference was not marked, except in the winter rainfall region, where CHIRPS (and to a lesser extent, Pegram) performed poorly. It is concluded that CHIRPS will have a role to play in future water resources studies. It is recommended that the study be extended to cover a larger sample of catchments with up-to-date rainfall and that the possibility of CHIRPS data being recalibrated for the winter rainfall area be investigated.
The emergence of collectively owned self-supply water supply systems in rural South Africa – what can we learn from the Tshakhuma case in Limpopo?
Authors: Moritz Hofstetter  , Barbara van Koppen  , Alex Bolding
Published: April 2021

Despite the rapid extension of public service delivery since the end of Apartheid, many rural citizens in South Africa still rely on their own initiatives and infrastructure to access water. They construct, improve, operate and maintain infrastructure of different complexities, from individual wells to complex collectively owned water schemes. While most of these schemes operate without legal recognition, they provide essential services to many households. In this article we will first provide an overview of the growing international body of literature describing self-supply as an alternative pathway for public service delivery. We then take a historical perspective on the role of communities and self-supply in South Africa and describe the emergence of six collectively owned, gravity-fed, piped schemes in Tshakhuma, Limpopo Province. We describe and compare these systems using key characteristics like resource access, investment, construction, operation, maintenance and institutional governance. We further assess their performance with regard to coverage, service level, reliability, governance structure, accountability and water quality. We do so because we are convinced that lessons learned from studying such schemes as locally adapted prototypes have the potential to improve public approaches to service delivery. The described cases show the willingness of community members to engage with service delivery and their ability to provide services in cases where the state has failed. The assessment also highlights problematic aspects of self-supply related to a lack of accountability, technical expertise and the exclusion of disadvantaged community members. By describing and assessing the performance of rural self-supply schemes, we aim to recognize, study and learn from such schemes. We consequently do not conclude this article by providing answers, but by raising some pertinent, policy-relevant questions.
Algorithm visualizers design technology
Authors:   Novosibirsk State Technical University, Russian Federation, Romanov Eugene , Romanenko Tatiana ,   Novosibirsk State Technical University, Russian Federation
Published: April 2021

The topic of the article relates to the introduction of such forms of education as visualizers of algorithms into the distance education system of Novosibirsk State Technical University.
Oral health-related quality of life in elderly and young patients with periodontal diseases
Authors: GÖKTÜRK Özge , UCAN YARKAC Fatma
Published: April 2021

Objective: Due to the increase in the prevalence of periodontal diseases, quality of life decreases with aging. The purpose of this study was to investigate the quality of life and periodontal disease in young adults and elderly individuals. Materials and Method: A total of 104 individuals, including 52 elderly patients with periodontal disease (Test group; 37 with gingivitis and 15 with periodontitis) (mean age 67.56 ± 3.12) and 52 young adult patients with periodontal disease (Control group; 37 with gingivitis and 15 with periodontitis) (mean age 27.88 ± 6.59), were included in the study. The patients’ quality of life was determined by the Oral Health Impact Profile-14 (OHIP-14) questionnaire. Clinical periodontal parameters (gingival index (GI), plaque index (PI), clinical attachment loss (CAL), and probing pocket depth (PPD)) were used in the evaluation. Results: In periodontitis, there was no difference in total OHIP scores between the groups (p>0.05), whereas, in gingivitis, OHIP scores were higher in elderly patients (p<0.05). While GI was significantly higher in elderly patients, PPD and CAL were significantly higher in young adult patients with periodontitis (p<0.05). OHIP sub-groups’ scores for "physical pain, psychological discomfort, and psychological disability" were significantly higher in elderly patients (p<0.05). Conclusion: Oral health-related quality of life was significantly lower in elderly patients with periodontal disease. While gingivitis had a significantly higher effect on the quality of life in elderly patients compared to younger patients, it was observed that there was no difference in both age groups in the presence of periodontitis. Improving oral health with atraumatic and effective treatment applications at early ages can prevent periodontal problems that may occur in advanced ages and increase the quality of life.
La cooperación española y la construcción de paz en Colombia (2012-2020): notas para la reflexión
Authors: Ríos Sierra Jerónimo
Published: April 2021

La siguiente nota de reflexión sirve como ejercicio exploratorio para entender cuál ha sido el alcance y significado de la cooperación española en la construcción de paz de Colombia, en donde tiene lugar el conflicto armado interno más longevo de América Latina. Analizando el período que transcurre entre 2012 y 2020, se revisan los diferentes planes directores de la cooperación española, así como los marcos de asociación país y las memorias de la AECID para poner en valor la aportación española de la cooperación en Colombia, primero, en términos generales, y específicamente, en lo que respecta a la construcción de paz. A modo de conclusiones, aunque la cooperación de España en Colombia ha sido muy importante, desde inicios de la década pasada comienza a reducirse muy significativamente en términos económicos, aunque mostrando una relativa continuidad en lo que al sentido de las intervenciones y las prioridades sociales y regionales se refiere. Así, a pesar de las dificultades y los cambios en las prioridades, se ha construido una agenda distintiva en lo que a construcción de paz y respaldo al Acuerdo con las FARC-EP se refiere, que merece la pena preservar.
La diplomacia de defensa de España en Iberoamérica: ¿una estrategia de poder blando?
Authors: Bueno Alberto , Gallego Cosme Mario J.
Published: April 2021

España despliega desde hace décadas su diplomacia de defensa hacia Iberoamérica y, a pesar el interés que esta cuestión ha suscitado, persiste una manifiesta ausencia de enfoques teóricos. Sin embargo, existe una creciente literatura científica que emplea el concepto de poder blando para explicar las implicaciones estratégicas de la diplomacia de defensa. Por esta razón, esta investigación adopta este marco conceptual para examinar esta área de las relaciones político-diplomáticas entre España e Iberoamérica con dos objetivos: primero, estudiar si las iniciativas encajan, en efecto, en este concepto del poder blando; y segundo, investigar su planteamiento estratégico. Para ello, realiza un análisis de los documentos político-estratégicos españoles de primer nivel, otras fuentes documentales oficiales y de centros de análisis, así como revisión de la bibliografía especializada. Los resultados señalan la ambigüedad y limitación de los objetivos estratégicos españoles, la pérdida de protagonismo de Iberoamérica en términos de interés para la defensa nacional o de comercio de industria de defensa, así como determinadas incongruencias entre los medios y los modos, y los fines. Las conclusiones discuten la inclusión acrítica de diversas iniciativas como diplomacia de defensa y la ausencia de un planteamiento estratégico desde un enfoque del poder blando.
Oscilaciones en las relaciones Brasil-España: entre el pragmatismo económico y el desconocimiento mutuo
Authors: Caballero Sergio
Published: April 2021

En este trabajo se abordan las relaciones político-diplomáticas entre España y Brasil desde un enfoque histórico de política exterior, entendiendo la política exterior como una política pública diseñada en base a las negociaciones entre actores diversos y tendente a satisfacer el bienestar de los ciudadanos. A través de un recorrido histórico por las relaciones entre estos dos países y en aras a analizar el estado de los lazos entre Brasilia y Madrid, en este artículo se desglosa en primer lugar la naturaleza de esas relaciones en las últimas décadas. Después, se incorporan las respectivas perspectivas de política exterior desde ambas cancillerías (el Palacio de Santa Cruz e Itamaraty), enmarcándolas en sus propios procesos regionales y a la luz de los constreñimientos contextuales y estructurales que modulan o delimitan las posibilidades de actuación en el ámbito internacional. Seguidamente se diseccionan las relaciones bilaterales en el escenario actual y finalmente se extraen una suerte de conclusiones o claves que sirvan de brújula para interpretar adecuadamente estas relaciones, sustentadas en una fuerte divergencia entre los agentes que diseñan las respectivas políticas exteriores.
Human Islet Isolation Media Preparation v2
Authors: Lyon James , F Spigelman Aliya , E Manning Fox Jocelyn , E Macdonald Patrick
Published: April 2021

This protocol describes the preparation of various media formulations required for the isolation and culture of human islets, as performed by the Alberta Diabetes Institute IsletCore. http://www.bcell.org/adi-isletcore.html
Nuclei Isolation from Tissue for 10x Multiome v1
Authors: Shi Minyi , K K Weimer Annika , P Snyder Michael
Published: April 2021

Nuclei Isolation from Tissue for 10x Multiome
ADI IsletCore Protocols for the Isolation, Assessment and Cryopreservation of Human Pancreatic Islets of Langerhans for Research Purposes v2
Authors: Lyon James , F Spigelman Aliya , E Manning Fox Jocelyn , E Macdonald Patrick
Published: April 2021

This collection of protocols describe the processes used by the Alberta Diabetes Institute IsletCore for the isolation of human pancreatic islets of Langerhans for research. In addition, protocols related to quality control and the cryopreservation of human islets are included. http://www.bcell.org/adi-isletcore.html The ADI IsletCore program is described in full here: Lyon J, Manning Fox JE, Spigelman AF, Kim R, Smith N, O'Gorman D, Kin T, Shapiro AMJ, Rajotte RV, MacDonald PE (2016)Research-focused isolation of human islets from donors with and without diabetes at the Alberta Diabetes Institute IsletCore. Endocrinology, 157(2): 560-569.
Sampling of Human Islets for Quality Control Purposes v2
Authors: Lyon James , F Spigelman Aliya , E Manning Fox Jocelyn , E Macdonald Patrick
Published: April 2021

This protocol described the sampling of human islets for quality control purposes, as performed by the Alberta Diabetes Institute IsletCore. http://www.bcell.org/adi-isletcore.html
Variable actual stiffness of guides in potash mine shafts
Authors: Pestrikova V. S. , Yarushin A. D. , Tarasov V. V. , Shkuratskiy D. N.
Published: April 2021

The article addresses serviceability of reinforcement in vertical mine shafts. The mathematical framework is presented for the dynamic processes in the capsule–reinforcement system. The main causes of the dynamic loads in the capsule–reinforcement system are discussed. The importance of the processes in the capsule–reinforcement system during movement of hoists in vertical mine shafts is emphasized. It is asserted that solely computational methods are not enough to analyze processes inside the capsule–reinforcement systems in shafts. It is required to examine actual parameters of shaft reinforcement, in particular, the actual stiffness of shaft guides. The actual measurement procedure of guide stiffness in potash mine shafts is presented. The full-scale tests data are set out in connection with the actual step of reinforcement in shafts. The actual and calculated values of stiffness of shaft guides are compared. Based on the obtained results, the variable stiffness coefficient is derived for the shaft guide stiffness for a few alternative of reinforcement step. Considering the described research findings and the many years-long experience gained in operation of mine shafts, the authors have drawn a conclusion on the necessity to take into account the factor of variable stiffness of guides in shaft design and construction in potash mines in the Upper Kama Potash–Magnesium Salt Deposit, especially in case when the shaft reinforcement step exceeds the project design standards.
Construction and operation of batching plants in difficult geological conditions of Upper Kama potash mines
Authors: Aptukov V. N. , Tarasov V. V. , Pestrikova V. S. , Ivanov O. V.
Published: April 2021

Scenarios of the component arrangement of batching plants in the system of a vertical mine shaft are discussed. The features of operation of batching plants in vertical shafts of potash mines are identified. The actual recorded damages generated in the lining of batching plants in the course of their longterm operation in potash mines are described. The geomechanical researches aimed to determine vertical convergence in batching rooms of mine shafts, as well as for monitoring of crack opening and displacements in sidewalls in the batching chambers are presented. The major results of the full-scale geomechanical observations are reported, and the main causes of fractures in concrete and reinforced concrete lining at junctures of shafts and batching rooms and shaft bins are identified. The set of the engineering solutions implemented for the protection of lining in batching facilities during construction of mine shafts is described, and its efficiency is evaluated. The mathematical modeling is carried out to estimate various negative impacts on deformation and fracture of concrete lining in shafts with regard to the time factor. From the modeling results, the dominant cause of concrete lining damage in batching chambers and in mine shaft is found. Based on the accomplished research results and actual long-term experience of operation of mine shafts, the most favorable factors are determined for the best design choices in construction and long-term maintenance-free operation of batching plants in potash mines of the Upper Kama Potash–Magnesium Salt Deposit.
Application of hydrogen peroxide to intensify in-situ leaching of uranium
Authors: Yusupov Kh. A. , Bashilova E. S. , Tsoy B. V. , Aleshin A. P.
Published: April 2021

The current goal in uranium mining is to ensure the maximum effect at minimized costs. One of the problems when using the in-situ leaching (ISL) technology consists in the incomplete mining of the process blocks due to premature uranium content reduction in the pregnant solutions, leading to increased mining times and excessive reagent consumption. The required complete block mining shall be ensured with the highest possible efficiency. The ISL technology is currently used for the mining of all hydrogenous uranium deposits in the Republic of Kazakhstan, which are often characterized by complex geological and hydrogeological conditions. One of these deposits, Semizbay, rates as complexity type III. The conditions at the deposit require increasing the redox potential of the solution by oxidizing Fe2+ into Fe3+. The article considers the addition of hydrogen peroxide to the leaching solutions to improve the redox potential with due account of the mining and geological features of the Semizbay deposit. The pilot tests have established that this oxidizing agent has a positive effect on the uranium content in the pregnant solution with the concentrations of 0.2–0.3 l/m3, provided that the concentration of sulfuric acid in the leaching solutions is within the range of 13–15 g/l. The studies allowed increasing the concentration of uranium in the pregnant solutions from 74 to 114 g/l (i.e., by over 50 %). The authors are grateful to the staff of the geotechnology department of the Semizbay mine, Semizbay-U LLP, for collecting the data and to the staff of the IVT-Zerde LLP laboratory (branch of the Semizbay mine) for the high-quality laboratory experiments during the pilot tests at the mine.
Modelling the reduction of zinc from oxide melt
Authors: Vusikhis A. S. , Selivanov E. N. , Leontiev L. I. , Tyushnyakov S. N.
Published: April 2021

For predicting the results of sparging processes to understand how much metal can be reduced from oxide melt, a method of thermodynamic modelling has been developed that ensures approximation to real systems in which the metallic phase and gases are removed from the liquid at a certain interval. The key principle of this method is that equilibrium is determined for every single portion of introduced gas, and the concentration of oxides of the reduced metals in each cycle is taken from the previous data. Such approach enables a very close simulation of real processes so that one can have an idea about the quality of reactions taking place in pyrometallurgical units. When the thermodynamic modelling method was applied to the processes of iron and nickel reduction, the obtained results well matched the experimental data. A comparative analysis was carried out to understand how the temperature T and the amount of introduced gas VСО or VН2 influence the process of zinc reduction from oxide melt. For the purposes of modelling, a B2O3 – CaO – ZnO melt was used with the B2O3/CaO ratio equal to 3 (which corresponds to the eutectic composition) and with the initial ZnO concentration in the range from 3 to 12 %; the temperature range used was 1273–1673 K. The concentration of zinc oxide СZnO in the melt, as well as the reduction degree Zn were analyzed. The correlation dependences СZnO, φZn = f(C0, T, VCO or VH2) are presented in the form of second order polynomials. Reduction of zinc with hydrogen is a more intense process than when zinc is reduced with carbon monoxide. Therefore, less gas is required to reach a similar reduction degree. A higher temperature facilitates the reduction of zinc while less СО or Н2 is required to achieve the target reduction degree φZn. Irrespective of the initial composition of the melt, it takes 1.5 times less hydrogen that carbon monoxide to obtain the unit mass of zinc with the process temperature being the same. The obtained data explain the changing zinc distillation performance when changing the temperature. The established relationships between CZnO and φZn and the temperature and the amount of introduced gas are useful for predicting the zinc distillation performance and can be used as basic relationships for analyzing experimental data. This research was funded by the Russian Foundation for Basic Research under the Project No. 18-29-24093мк.
Reconstruction of the Taguchi Orthogonal Arrays with the Support Vector Machines Method
Authors: YAZAR Selçuk
Published: April 2021

Design of Experiment (DOE) is a widely used method for examining experiments especially in industrial production and robust design processes. This method is a set of statistical approaches in which mathematical models are developed through experimental testing to estimate possible outputs and given input values or parameters. The method aims to determine the main factors that affect the results with the smallest number of experimental studies. In this study, L16 (2^15) orthogonal array, which was used in the Taguchi parameter design was reconstructed with the Support Vector Machines learning model and the Pearson VII kernel function. With this model, array elements were successfully classified in 87.04%. The new and original array were compared and 3.8% difference was measured between their Signal to Noise (S / N) ratios in an exemplary experiment.
Spectrum Occupancy Measurements in Cellular Frequency Band in Samsun
Authors: KORUNUR ENGİZ Begüm , RAJAB Yousif Ali Rajab
Published: April 2021

In this study, available spectrum parts in GSM900, LTE800, LTE900, GSM1800, LTE1800, UMTS2100 and LTE2600 were determined. The measurement campaigns were performed at 115 different locations in Samsun city center at the most active time of a day using RF Explorer 6G Combo analyzer device. The spectrum utilization rates were determined using energy detection technique (EDT), and average spectrum occupancy technique (ASOT). The thresholds were chosen manually as -40, -45, -50, -55, -60, -65, -70, -75 dBm, and as 10-dB above the noise floor, as recommended by International Telecommunication Union (ITU), and spectrum utilization was evaluated through EDT and ASOT. Obtained results show that at most of the measurement locations spectrum occupancy percentages calculated via EDT and ASOT very close to each other. Based on the results UMTS2100 band showed the highest average spectrum occupancy i.e. 33.91% and the overall average spectrum occupancy rate was found to 22.72%. Additionally, at 50% of the measurement locations occupancy percentage was below 33% for all services. The average occupancy over GSM900 band was between 0,87% - 66.61% according to the predetermined threshold. It was also found that the bands LTE1800 and LTE2600 were mostly occupied for the thresholds below -60 dBm whereas the measured spectrum was mostly vacant for -40 dBm. This led us to infer that there is a great potential for share some of UHF band for cognitive radio applications and future 5G systems.
How does artificial intelligence effect on the assessment of lung damage in COVID-19 on chest CT scan?
Authors: Morozov Sergey P. , Chernina Valeria Y. , Andreychenko Anna E. , Vladzymyrskyy Anton V. , Mokienko Olesya А. , Gombolevskiy Victor A.
Published: April 2021

BACKGROUND: During the pandemic, computed tomography (CT) was one of the most important tools for assessing COVID-19-related lung changes. In COVID-19 patients, radiologists in Moscow used the adapted CT0-4 scale to visually assess the dependence of the severity of the general condition on the nature and severity of radiological signs of changes in the lungs based on computed tomography. In a large stream of scans, the doctor may miss findings and make errors in assessing the volume of lung damage, so the use of AI services in outpatient healthcare during a pandemic can be beneficial.
AIM: The goal of this study is to compare the distribution of CT0-4 categories designed by radiologists with the results of AI services processing and categories formed without AI services.
METHODS: We used retrospective study design, full study protocol is registered on ClinicalTrials.gov (NCT04489992). The results of primary CT scans with the CT0-4 categories were analyzed in outpatient medical institutions of the Health Department from April 08, 2020, to December 01, 2020, and separately for November (from November 01, 2020, to December 01, 2020). CT was performed on 48 computed tomographs in accordance with standard protocols, and the data was processed by the single radiology information systems. CTs in the test group received AI services, while CTs in the control group did not. The analysis includes five AI services: RADLogics COVID-19 (RADLogics, USA), COVID-IRA (IRA labs, Russia), Care Mentor AI, COVID (Care Mentor AI, Russia), Third Opinion. CT-COVID-19 (Third Opinion, Russia), and COVID-MULTIVOX (Gammamed, Russia). Moreover, AI services are encoded at random.
RESULTS: The CT scan results of 260,594 patients were examined (m/f % = 44/56, mean age = 49.5). The test group consisted of 115,618 CT scans, while the control group consisted of 144,976 CT scans. Depending on the specific AI service, CT0 was established by 2.318.5% less than the control group for different subgroups of categories. The categories CT3-4 were established by 4.727.6% less than without AI, and the categories CT4 by 4060% less than without AI (p 0.0001). For November (from November 01, 2020, to December 01, 2020), the CT scan results of 41,386 patients were analyzed (m/f % = 44/56, average age = 53.2 years). The test group consisted of 28,881 CT scans, while the control group included 12,505 CT scans. Depending on the specific AI service, CT0 was established by 12.6% less than the control group for different subgroups of categories. Further, the categories CT3CT4 were established by 0.215.7% less than without AI, and the categories CT4 were established by 25% less than without AI (p = 0.001).
CONCLUSION: The use of AI services for primary CT scans on an outpatient basis reduces the number of CT0 and CT3CT4 results, which can influence the therapeutic approach for COVID-19 patients.
Reasons of the high rate of the population incidence of micosis of feet: role of doctor and patient
Authors: Sokolova Tatiyana V. , Malyarchuk Alеxandr P. , Gladko Viktor V. , Montes Rosel Ksenia V.
Published: April 2021

BACKGROUND: Mycoses of the feet is a significant interdisciplinary health problem.
AIM: To analyze and systematize the causes contributing to the high incidence of foot mycoses in Russia.
MATERIALS AND METHODS: With the use of an anonymous questionnaire survey, the attitude of patients toward their health and the opinions of dermatologists and related specialists about the causes contributing to the high incidence of foot mycoses in the Russian population were analyzed.
RESULTS: The reasons contributing to the high incidence of foot mycoses in Russia are ranked into four groups: (1) depend on the activities of the dermatological service; (2) are related to the level of professional training of doctors of related specialties; (3) objective organizational reasons for doctors of related specialties; (4) depend on the patients attitude to their health.
CONCLUSION: The data obtained can be used to develop a complex of therapeutic and prophylactic measures to improve medical care for this contingent of patients.
Microbiome and acne vulgaris
Authors: Ma Ziyuan , Kochergin Nikolay G.
Published: April 2021

Acne vulgaris is a highly prevalent inflammatory skin disease involving sebaceous follicle. Although the pathogensis of acne remains uncertain, skin microbes are considered to plays an essential role in acne vulgaris. Cutibacterium acnes is the most important microbe in acne pathogenesis and its several processes: colonization, over-proliferation and inflammation have long been thought to contribute to the disease. Moreover, Staphylococcus epidermidis and Malassezia also synergistically collaborate with Cutibacterium acnes. Besides, given the growing number of patients who are treatment resistant, assessments are needed on phenotypic changes in the skin microbiome with retinoids and antibacterial therapy. Further research on the role of microbes in the pathogenesis of acne and the relationship between pathogenic microbes is expected to provide a new theoretical basis for clinical treatment of acne.
Computer network attacks as an act of aggression in the context of the development of modern international relations: pros and cons
Authors: Lobach Dmitriy V. , Smirnova Evgeniya A.
Published: April 2021

The article analyzes the conflicting approaches to the possible recognition of computer network attacks as an act of aggression in the focus of modern international relations and trends in scientific and technological progress. The question raised in the article is as follows: is aggression against another state possible through the exclusive use of cyber weapons? To solve the indicated problem, the scholastic method of conducting a discussion is used, in which two series of contradictory arguments regarding the subject of discussion are put forth, and the conclusion summarizes the general conclusion based on particular theses. The conclusion is argued that the historically established definition of aggression in modern conditions of development of scientific and technological progress does not meet the interests of international peace and security, since new types of force of destructive influence constantly appear, which can generate consequences comparable in scale and severity to the consequences of using conventional weapons. However, there are still some problematic moments that arise in connection with the qualification of cyberattacks as a crime of aggression, requiring understanding and resolution in accordance with the development of the science of international law and law enforcement practice in the context of international relations.
Научное рецензирование. Лучшие практики и рекомендации
Authors: Spyns Peter , Vidal Maria-Esther
Published: April 2021

This booklet aims to tackle this problem by providing a practical introduction to the practice of peer reviewing. Although it mainly focuses on paper reviewing for scientific events in the domain of computer science and (business) informatics, many of the principles, tips, tricks, and examples are generalizable to journal reviewing and other scientific domains. Some of the principles and tips can also be applied when reviewing proposals for research projects or grants. In addition, many aspects of this booklet will also benefit authors of scientific papers (even outside computer science) as they will gain more insight into how papers are reviewed and hence where they have to pay attention to when writing their papers.
Constituindo-se Professora que Ensinará Matemática nos Anos Iniciais: o que Revelam as Narrativas Quanto a Alfabetização Matemática?
Authors: Silva Américo Junior Nunes da
Published: April 2021

ResumoEste artigo é recorte de um doutoramento, resultado de uma pesquisa narrativa, e objetiva investigar o que revelam as narrativas de estudantes do curso de Pedagogia da Universidade Federal de São Carlos (UFSCar), construídas durante dois encontros da disciplina “Matemática: conteúdos e seu ensino”, sobre a ludicidade, o ensinar matemática no ciclo de alfabetização e o constituir-se professora que ensinará matemática nos anos iniciais. Nesse percurso, escolhemos as narrativas enquanto método e fenômeno a ser estudado. Constituímos diários de formação, produzidos pelas cinco participantes e por mim, e as entrevistas narrativas realizadas, como textos de campo. O processo de análise realizado se deu por meio da análise narrativa. As narrativas produzidas revelaram algumas dificuldades conceituais sobre a matemática e o processo de alfabetização matemática. Ao longo dos encontros, percebemos que as diferentes estratégias formativas propostas contribuíram para repensar essas crenças e ressignificar essas marcas negativas e as dificuldades que apresentaram.Palavras-chave: Alfabetização Matemática. Formação Inicial de Professores. Narrativas. Diários de Formação.
AbstractThis article is an excerpt from a PhD, the result of a narrative research, and aims to investigate what the narratives of students in the Pedagogy course at the Federal University of São Carlos (UFSCar) reveal, built during two meetings of the discipline “Mathematics: Contents and their teaching ”, On playfulness, teaching mathematics in the literacy cycle and becoming a teacher who will teach mathematics in the early years. Along this path, we chose narratives as a method and phenomenon to be studied. We constituted the training diaries, produced by the 05 participants and mine, and the narrative interviews carried out, as field texts. The analysis process carried out took place through narrative analysis. The narratives produced revealed some conceptual difficulties about mathematics and the mathematical literacy process. Throughout the meetings, we realized that the different training strategies proposed contributed to rethink these beliefs and reframe these negative marks and the difficulties they presented.
Keywords: Mathematical Literacy. Initial Teacher Training. Narratives. Training Diaries