bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination and Classification of Importance of Attributes Used in Diagnosing Pregnant Women's Birth Method
Authors: ÇELİK Sümeyye
Published: December 2020

The rapid development of information technologies enables successful results in computer-aided studies. This has led researchers to investigate the usability of technologies such as computer and software supported systems, machine learning, and artificial intelligence in many studies. One of these areas is health. For example, in order not to risk the condition of the mother and baby, in some cases, it is very important to correctly determine the times when the cesarean operation, which is mandatory, is mandatory. In this context, in order to make a faster and more accurate decision, it is very important to determine which attributes and how important the level is in making obligatory cesarean. In this study, to determine whether or not caesarean is necessary in the literature, the importance level of the five criteria taken into consideration has been determined and an attribute determination has been carried out and then a classification has been made. Although the same data set was previously classified with different methods, no study was found on determining the significance levels of the attributes and using artificial neural networks as a method. For this reason, in this study, the feature was determined using an adaptive nerve-fuzzy classifier and classified using artificial neural networks. When the results are examined, it is concluded that the importance levels of the attributes are different. Although the values such as accuricy, Sensitivity, and Specificity calculated to evaluate the classification results were found to be quite high for the training set, it was observed that the desired success was not achieved in the test data. While this result is promising, it also reveals the need to increase the learning performed with larger data sets.
Torsional Vibrations of the Steam Turbine Shaft Line and Estimation of the Residual Life of Its Elements
Authors:   Toraighyrov Pavlodar State University, Grabovskii Vladimir
Published: December 2020

A comparative quantitative assessment of the damage and residual life of the shaft line elements for differ-ent types of high-power steam turbines at the end of their design life is made by mathematical modeling. The analysis covers all elements of the shaft line: from the steam turbine Central pump to the turbine generator ex-citer. The simulated circuit includes turbo generators, transformers, gate converters, AC and DC power lines. When modeling, an approach is used from the position of proper coordinates, which provides maximum meth-odological consistency of the models of the listed devices and allows you to directly reproduce electromagnetic and mechanical transients with the determination of instantaneous values of currents, voltages, electromagnet-ic and torsional moments. To estimate damage, we used the deformation criterion for soft and hard loads in the zone of low-cycle and force criterion in the zone of multi-cycle fatigue. The influence of the number of starts and running time of a steam turbine on the damage and residual life of its shaft elements is studied. When de-termining the remaining life, in addition to starts, other abnormal operating modes of the turbo generator were taken into account during the turbine operating time: short circuits and their disconnections, unsuccessful high-speed automatic re-activation, subsynchronous resonance due to both the operation of the control system of the PPT and the automatic generator excitation regulator. The influence of attenuation of electromagnetic transients in the generator and damping of torsional vibrations on the degree of reduction of the residual life of the shaft elements is analyzed. The results obtained can be used for a comprehensive solution of the issue of further operation of steam turbines that have spent their design life.
Comparison of Designs of a Valve-Inductor Motor of an Electric Spindle Drive
Authors:   Rostov State Transport University, Kolpakhch'yan Pavel , Lobov Boris ,   Platov South-Russian State Polytechnic University (NPI), Peregudov Oleg ,   Platov South-Russian State Polytechnic University (NPI)
Published: December 2020

When designing electric machines, in particular, the valve-inductor motor of the electric spindle drive, there is a need to compare several designs of such machines in order to choose the most rational one. Based on the given initial data and preliminary calculations, two design variants of the engine were selected: three-phase and five-phase. For each variant, the FEMM v 4.2 software package has been used to calculate optimal geometric ratios based on the maximum of the average moment value. Then, for the optimal variants of a three-phase and five-phase machine, calculations of the voltage, current, and flow coupling of the stator phase, as well as the electromagnetic moment, were performed. It is shown that in a five-phase electric machine, the total electromagnetic moment has several times lower pulsations compared to the three-phase version.
On the Issue of Determining the Engine Power of Tensioners When Winding Products Made of «Wet» Composite Material
Authors:   Platov South-Russian State Polytechnic University (NPI), Mikitinskiy Alexander
Published: December 2020

Products made by the method of «wet» winding from composite material are widely used in various indus-tries. The quality of future products is largely determined by the tension with which the «wet» tape is placed on the product. Until now, the electric motor of the tensioning device was selected from the condition of providing the specified maximum tension value of the composite tape, without taking into account the specific features of the tensioning device used and the geometry of the wound product. However, when winding a product with a complex geometric shape, dynamic moments occur in the electric drive, which cause additional heating of the engine. The paper analyzes the tensioning devices used for winding. They are grouped into two classes: linear and angular movement of tension rollers. For the considered tensioning devices, analytical expressions are ob-tained that relate the tension during winding with the force that the Executive electric motor must provide in static and dynamic modes. A method for selecting the drive power of tensioning devices is proposed, which takes into account the features of winding composite products made of «wet» composite material. As an exam-ple, the drive of a tensioning device is calculated when winding a pressure cylinder with a diameter of 0.2 m. the Calculations are carried out taking into account the possibility of using a worm self-braking gearbox or a planetary gearbox. Graphs of the dependence of static and dynamic moments on the motor shaft are plotted. It is shown that the use of a worm gearbox requires a more powerful drive, but when using a planetary gearbox, the electric motor must be able to stand under full load. The results obtained in this work can be used in the de-sign of new winding equipment or modernization of existing ones.
New Research Results of Algorithms for Analysis of Changing Electric Circuits
Authors:   Platov South-Russian State Polytechnic University (NPI), Lebedev Ivan , Savelov Nikolai ,   Platov South-Russian State Polytechnic University (NPI)
Published: December 2020

New research results in the field of accelerated analysis of linear and linearizable electrical circuits with variable elements are presented. The considered algorithms are based on a new modification of Gaussian elim-ination for solution of systems of linear equations. The researches was directed on a systematic thorough study of the phenomenon of quasi-stabilization of the error discovered by the authors during multiple repeated cir-cuit analyzes. The Sherman-Morrison algorithm and the iterative refinement algorithm are considered as alter-natives. To control the results of numerical experiments, the representation of floating-point numbers in the bi-nary128 format of the IEEE 754 standard is used. A method for the machine formation of mathematical models of circuits with an unlimited number of elements is proposed.
Solving the Problem of Determining the Maximum Fault Tolerance of Distributed Information Processing Systems with a Limit on Their Reactivity
Authors:   Platov South-Russian State Polytechnic University (NPI), Scoba Andrey , Mikhaylov Vladislav ,   Platov South-Russian State Polytechnic University (NPI), Ayesh Achmed Nafea Ayesh  ,   Platov South-Russian State Polytechnic University (NPI)
Published: December 2020

The use of exponential Queuing networks for calculating the reliability characteristics of distributed in-formation processing systems is proposed. This allows you to naturally tie the reliability characteristics of the system (failure rates) with its technical and operational characteristics (the average response time of the system to user requests). And also reduce the problem to calculating stationary probabilities of Queuing network States. The article formulates and solves the optimization problem of finding the maximum fault tolerance of distributed information processing systems implemented on the basis of a two-level and three-level client-server architecture with a fixed value of the average system response time to user requests. The problem of determining the fault tolerance indicators of distributed information processing systems is reduced to the problem of deter-mining the stationary probabilities of Queuing network States. The article presents the results of numerical ex-periments. The analysis of the obtained results shows the prospects of using these models to obtain estimates of the reliability characteristics distributed information processing systems in various subject areas.
Calculation of Additional Losses in Windings of Permanent Magnet Motors Using the Femm Package
Authors:   «Emtech Ltd.» company, Pakhomin Leonid , Pakhomin Sergey ,   Platov South-Russian State Polytechnic University (NPI)
Published: December 2020

The calculation of additional losses in the windings of permanent magnet synchronous motors is proposed to be performed using the FEMM package. The article describes a system of equations that allows to determine the distribution of instantaneous values of currents in the elementary wires of the winding. As an example, a low-voltage permanent magnet motor with concentrated windings on a stator is considered. To determine the matrix of inductances of elementary phase wires, the FEMM program was used. To speed up the calculations, a control script for FEMM (in the lua scripting language) was used, which made it possible to automatically de-termine the matrix of own and mutual inductances for a given distribution of elementary wires in a slot. The re-sults of calculating the instantaneous values of the currents in the elementary wires of the winding are used to determine the additional losses. Variants of the distribution of elementary conductors in a slot are considered, the corresponding coefficients of increasing losses in the winding are determined.
Motion Control of an Electromechanical Micro Robot
Authors:   Neftekamsk branch of Bashkir State University, Safiullin Ruzil
Published: December 2020

Currently, the development of innovative technologies in the field of electromechanics are microelectrome-chanical systems. They are widely used both in various industries and in domestic conditions of human life. An algorithm and a mathematical model of the design of an electromechanical composite microrobot have been developed. A system of equations of mechanics and electrodynamics was used to describe its metrological char-acteristics. By solving this system of equations, a theoretical analysis of the operation of its engine with a spiral secondary elastic element is carried out. Using the mechatronic approach, the buoyancy and coordination of its functional modules are studied. The results of this article will be useful for engineers involved in the design and operation of micro robots using robotic systems in the fields of biotechnology and biomechanics.
Automatic System Design Humification of Sinter Burden in Aglomeration Shop JSC «Ural Steel»
Authors:   Novotroitsk branch of the National University of Science and Technology «MISIS», Litsin Konstantin , Belykh Darya ,   Novotroitsk branch of the National University of Science and Technology «MISIS»
Published: December 2020

The authors propose a comprehensive solution to decrease in humidity control sinter charge sinter shop JSC Ural Steel. The main task of sinter production is the maximum productivity of the sinter machine with a sat-isfactory agglomerate quality. One of the key parameters affecting the sinter belt performance is the moisture content of the humidity sinter. Changes in the granulometric and chemical composition and physical and me-chanical properties of the components of the charge necessitate the search for new values of the optimum hu-midity of the charge. A system for automatic control of sintering machine productivity has been developed. Au-tomatic control is based on the principle of operation of a stepping type extreme regulation system with memo-rizing the extremum (maximum) of the output parameter. The simulation of the pump electric drive is implement-ed based on the developed automatic control loop for the moisture content of the sinter charge. Implementation of the proposed system for automatic wetting of the sinter charge will increase the productivity of the sinter machine by 1,4 % while reducing the water consumption by 1,7 %.
Feature of Voltage Transformers Operation in the Direct Current Schemes of Ice Melting on Overhead Transmission Lines
Authors:   Platov South-Russian State Polytechnic University (NPI), Zasypkin (jr.) Alexander , Shchurov Artyom ,   Platov South-Russian State Polytechnic University (NPI), Zasypkin Alexander ,   Platov South-Russian State Polytechnic University (NPI)
Published: December 2020

It is well known that electromagnetic voltage transformers (VT), included in the direct current scheme of ice melting (SIM) on overhead transmission lines (OTL), must be switched off when the SIM is assembling and turned on during disassembling. This action increases the time of the power line output from work and reduces the reliability of the power system. It is noted that capacitance VTs used in the electrical networks of 110-500 kV are not subject to the dangerous influence of DC voltage. Three variants of capacitors installation for elec-tromagnetic VT protection from direct voltage at which it is not required to switch off VTs are considered. A conclusion was made on the conditions of applicability of each variant based on the analysis of basic SIM. The article includes the necessary for practical use equivalent circuits and the values of constant voltages on the VTs in the basic direct current schemes of ice melting on overhead transmission lines. The method and an exam-ple of parameters calculation of the capacitors' block and additional resistor, providing the required accuracy class of VT at its constant inclusion as in the normal scheme, and in the scheme of ice melting, are given.
Part 2: Reactive Compensation of the Linear Load in Three-Phase Four-Wire Systems Supplied with Asymmetrical Sinusoidal Voltage Following Currents’ Physical Components Theory
Authors:   Politechnika Bialostocka, SOLJAN Zbigniew
Published: December 2020

Four-wire systems are the most common ones in everyday life. Electrical installations within the home, office, or industrial plant are mostly four-wire installations. Receivers connected to such a system are mainly single-phase loads, which from the power connection are an unbalanced three-phase load. Apart from, the load imbalance, the supply voltage also has some asymmetry. Voltage asymmetry, load imbalance, the design of reactance compensators are issues that were not simultaneously included in the power equation in fourwire systems. This article presents the mathematical fundamentals of the construction of reactance compensators operating in voltage asymmetry.
Victoria Filminde Mekân-Zamansal Sürekliliğin Dalım Üzerindeki Etkisi
Authors: YÜCEL Ali Altan
Published: December 2020

Derin bir şekilde odaklanma, dâhil olma, dalıp gitme anlamlarına gelen dalım (immersion) terimi, özdeşleşme temelli tüm anlatıların ortak hedefidir. Kişi kendisini okuduğu bir kitaba ya da seyrettiği bir filme kaptırdığında bir dalım yaşar. Belirli bir mekân ve zamanda gerçekleşen olayların kesintisiz olarak aktarılması anlatımda mekân-zamansal sürekliliği oluşturur. Mekân-zamansal süreklilik özellikle içerdiği gerçekçilik dolayısıyla dalımı oluşturan etmenlerden birisidir. Filmde mekân-zamansal sürekliliği sağlamanın en etkin yolu kurgunun kullanılmamasıdır. Araştırmaya konu olan Schipper’in Victoria adlı filmi tek çekim olması ve gerçekçiliğiyle ile öne çıkmaktadır. Örnek olay incelemesi yönteminin kullanıldığı bu nitel araştırmada, Victoria’daki mekân-zamansal sürekliliğin dalım üzerindeki etkisi araştırılmıştır. Araştırmanın bulgularına göre, gerçekçilik öznel bir kavram olması nedeniyle Victoria’da dalıma göreceli olarak katkı sağlamaktadır. Filmde fiziksel dalım gösterim salonu, geniş çerçeve oranı ve çevresel ses bileşimi aracılığıyla gerçekleşirken, zihinsel dalımda (buradalık) senaryodan kurguya kadar filmin tüm ögelerinin etkisi vardır. Victoria’daki mekân-zamansal sürekliliğin dalımı çoğunlukla desteklediği görülmüştür. Ancak zihinsel dalımın öznel bir his olması nedeniyle filmde mekân-zamansal sürekliliğin etkisi nesnel olarak saptanamamıştır. Bununla birlikte Victoria’nın bir anlatı filmi olmasından hareketle senaryodaki mekân-zamansal sürekliliğin filmdeki zihinsel dalımın temel etmenlerinden biri olduğu söylenebilir. Zihinsel dalımdaki birincil etmenlerin ise senaryodaki geciktirim ve özdeşleşme unsurları olduğunu söylemek mümkündür. Çünkü seyircinin öyküye olan ilgisini ve katılımını sağlayan temel unsurlar bunlardır. Sonuç olarak Victoria filminde mekân-zamansal sürekliliğin dalımın birincil etmeni olmadığı varsayımında bulunulabilir.
Genotyping of the rs1695 polymorphism of the GSTP1 gene by PCR-RFLP v1
Authors: Barletto de Sousa Barros Jéssica , de Faria Santos Kamilla , Morais Azevedo Rômulo , Pereira Dantas de Oliveira Rayana , Carolina Dourado Leobas Ana , da Cruz Pereira Bento Dhiogo , da Silva Santos Rodrigo , Adamski da Silva Reis Angela
Published: December 2020

Glutathione S-transferases (GSTs) are enzymes that act in the cellular detoxification of harmful compounds. Due to the role of the GSTP1 isoenzyme in the brain, the presence of the single nucleotide polymorphism (SNP) rs1695 in the GSTP1 gene may play an important role in the development of neurodegenerative diseases through oxidative stress, one of the main pathogenic mechanisms associated with the degeneration and death of motor neurons.Thus, this protocol provides a standardized methodology for genotyping the rs1695 polymorphism in the GSTP1 gene through polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (PCR- RFLP). This polymorphism consists of the exchange of adenine for guanine at position 313 (codon 105), which causes the substitution of amino acid isoleucine (Ile) for valine (Val), resulting in a decreased Pi enzyme activity. Polymorphism genotyping techniques have been of great interest in determining the genetic association of several polymorphisms with different diseases, and therefore this protocol may facilitate future genetic studies.
“Doing” mindsets in the classroom: A coding scheme for teacher and student mindset-related verbalizations
Authors: De Ruiter Naomi M. P. , Van der Klooster Katja N. , Thomaes Sander
Published: December 2020

There is a growing body of research showing the crucial role that students’ growth versus fixed ability-mindsets have in their school achievement, enjoyment, and resilience. The overwhelming majority of this research adopts a variable-oriented approach. As a result, little is known about how teachers and students co-regulate each other’s mindsets within classroom interactions. This manuscript addresses the need for more person-oriented research that examines how teachers and students do mindsets in naturalistic settings, i.e., their mindset-related verbalizations. In this manuscript, we provide a coding scheme to study the moment-to-moment dynamics of mindset-related verbalizations of both teachers and students within Science, Technology, Engineering, and Mathematics (STEM) contexts: The STEAM (Student-TEAcher-Mindset) coding scheme. We demonstrate the utility of the coding system through content and ecological validity, inter-rater reliability, and a case study of STEAM-generated time-series data. We show how these data can be used to chart moment-to-moment dynamics that occur between teacher and student. The coding scheme provides teachers and researchers with a practical tool for analyzing how person-specific mindset-related language can wax and wane in the context of peer and teacher interactions within STEM lessons.
A study of breast-feeding practices among rural women
Authors:   Assistant Professor, Community Medicine, RKDF Medical College and Research Centre, Jat Khedi, Hoshagabad Road, Bhopal, Madhya Pradesh, India, Patel Dr. Santosh , Nigam Dr. Kamlesh K ,   Associate Professor, Department of Community Medicine RKDF Medical College and Research Centre, Jat Khedi Hoshagabad Road, Bhopal, Madhya Pradesh, India, Babu Dr. G. Chitti ,   Assistant professor, JNU Medical College and Hospital, Jagathpura, Jaipur, Rajasthan, India, Kadali Dr. SLDV Ramana Murty ,   Associate Professor, Department of Pharmacology, JNU Institute of Medical Sciences and Research Center, Jaipur, Rajasthan, India
Published: December 2020

Introduction: Breastfeeding is an unequalled way of providing ideal food for the healthy growthand development of infants. As per the national family health survey-3 (NFHS-3), only 46% of theIndian infants between 0 and 6 months are exclusively breastfed. Hence the following study wasdone to know the practice of breastfeeding in mothers of rural and urban areas of India. Materialsand Methods: The study was conducted in a rural and urban area, which is under theadministrative control of a tertiary care hospital. All lactating mothers having babies up to 1 yearwere included in the study. Results: The mean age was 26.73 years (SD = 2.53), and 40.4 % ofmothers were below 20-24 years of age. A large proportion (77.8%) were of the Hindu faith. Mostmothers had education beyond primary school. 35.1% of participants were mothers of 2 or morechildren. A large percentage (74.7%) of study participants were delivered in a hospital. Exclusivebreastfeeding was practiced by 73.1% of mothers. 78.3% of a mother gave first breast milk i.e.colostrum to their new-borns. Still, 46.3% of mothers feed their child with honey, Ghutti, plainwater, artificial milk, sugar water, etc., before starting breastfeeding. Conclusions: The counselingshould be continued after the delivery of the baby for continuous education to the mother about theproper care of newborn, initiation of breastfeeding, the information regarding the advantages andduration of breastfeeding, the importance of colostrum feeding, the timing of weaning needs to beprovided
Assessment of patient satisfaction with inpatient services at secondary level setting
Authors:   Assistant Professor, Department of Community Medicine, Government Villupuram Medical College, Villupuram, Tamil Nadu, India, Dhanaraj Dr. Saravana kumari Arumugham , Selvi Dr. D. Thamarai ,   Associate Professor, Rajah Muthiah Dental College, Chidambaram, Tamilnadu, India, Kumar Dr. Ramasamy Rajesh ,   Research Scientist, College of Agriculture and Biotechnology, Zhejiang University, Hangzhou, China PR, Paul Dr. Sayan ,   Research Scholar, Department of Biotechnology, Manonmaniam Sundaranar University, Tirunelveli, Tamil Nadu, India
Published: December 2020

Background: Continuous quality improvement is linked to the use of timely and useful feedbackfrom clients. Patients constitute the hospital’s direct clientele. The overall satisfaction is an importantaspect of the service itself and it is considered to be an important outcome measure for healthservices. Patient care is not considered to be of high quality unless the patient is satisfied.Objective: To assess the level of satisfaction with available health services among inpatientsattending secondary level hospital. Methods: A cross-sectional study was conducted usingpretested, semi-structured questionnaire among 100 inpatients attending Government HospitalChidambaram, Tamil Nadu. Systematic random sampling was used. Results: 96% participants weresatisfied with the attitude of doctors and nurses, 80 % were highly satisfied with the cleanliness ofhospital campus,82 % were highly satisfied with lab services, 83% satisfied with food services. 92%were satisfied with the speedy admission to the ward, 74% satisfied with the ward facilities. 86 %gave a neutral response for other amenities,26 % satisfied with a drinking water facility. Overallsatisfaction among inpatients was a mean of 3.9 out of 5 (78%). Socio-demographic characteristicswere not significantly related to overall satisfaction scores. Conclusion: Patients were generallysatisfied with the hospital facilities. Patients input on various deficiencies needs to be addressed bythe hospital leadership to achieve consumer delight.
Robust optimization for U-shaped assembly line worker assignment and balancing problem with uncertain task times
Authors: Yılmaz Ömer Faruk
Published: December 2020

Awareness of the importance of U-shaped assembly line balancing problems is all on the rise. In the U-shaped assembly line, balancing is affected by the uncertainty associated with the assembly task times. Therefore, it is crucial to develop an approach to respond to the uncertainty caused by the task times. When the great majority of existing literature related to uncertainty in the assembly line is considered, it is observed that the U-shaped assembly line balancing problem under uncertainty is scarcely investigated. That being the case, we aim to fill this research gap by proposing a robust counterpart formulation for the addressed problem. In this study, a robust optimization model is developed for the U-shaped assembly line worker assignment and balancing problem (UALWABP) to cope with the task time uncertainty characterized by a combined interval and polyhedral uncertainty set. A real case study is conducted through data from a company producing water meters.
Extended RFM logit model for churn prediction in the mobile gaming market
Authors: Perisic Ana , Pahor Marko
Published: December 2020

As markets are becoming increasingly saturated, many businesses are shifting their focus to customer retention. In their need to understand and predict future customer behavior, businesses across sectors are adopting data-driven business intelligence to deal with churn prediction. A good example of this approach to retention management is the mobile game industry. This business sector usually relies on a considerable amount of behavioral telemetry data that allows them to understand how users interact with games. This high-resolution information enables game companies to develop and adopt accurate models for detecting customers with a high attrition propensity. This paper focuses on building a churn prediction model for the mobile gaming market by utilizing logistic regression analysis in the extended recency, frequency and monetary (RFM) framework. The model relies on a large set of raw telemetry data that was transformed into interpretable game-independent features. Robust statistical measures and dominance analysis were applied in order to assess feature importance. Established features are used to develop a logistic model for churn prediction and to classify potential churners in a population of users, regardless of their lifetime.
Export and total factor productivity of EU new member states
Authors: Jaksic Sasa , Erjavec Natasa , Cota Boris
Published: December 2020

The common denominator of the European Union’s (EU) strategic long-run documents is the role of total factor productivity in fostering future growth and competitiveness. Hence, this article analyses the impact of total factor productivity on export competitiveness in EU new member states (NMS). As opposed to the stagnation of the growth of total factor productivity in the advanced economies, EU NMS exhibited stronger growth that was interrupted due to the 2008 economic and financial crisis. After the crisis, the growth continued but it was not as strong as before. The results of the empirical analysis confirm the vital role of total factor productivity for the export competitiveness of the EU NMS. However, the results also point to the fact that the impact of total factor productivity on export competitiveness is not that beneficial in the countries where the value of total factor productivity has not returned to the pre-crisis level.
Defining the Prevalence and Predictors of Restrictive and Obstructive Airway Pattern in a Non-Selected Malaysian Population
Authors:   Respiratory Unit, Department of Medicine, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia., Ban Yu-Lin Andrea
Published: December 2020

The incidence of chronic obstructive pulmonary disease (COPD) in Malaysia appear to be increasing. To date, there are no local studies describing restrictive and obstructive airflow limitation patterns using spirometry. We conducted a crosssectional study to determine the prevalence and predictors of airflow limitation symptoms by screening for COPD symptoms with the COPD Population Screener (COPD-PS) questionnaire and determined the airflow limitation using the new hand-held device, AirSmart®. We recruited 265 subjects. Eleven percent had restrictive pattern and 16% had obstructive pattern. Twenty percent of subjects had COPD-PS score of more than five. In the obstructive pattern group, 74% were active or ex-smokers (p=0.03, p<0.01), whilst those with restrictive pattern were more likely to be heavier with a body mass index (BMI) of more than 23 (OR 2.52, 95% CI: 1.02-5.62) (p<0.01). There was a negative correlation between forced vital capacity and BMI (r=-0.5813, p<0.001). We found a high prevalence restrictive pattern of airflow limitation using the new AirSmart® Spirometer. There appeared to be a large proportion of undiagnosed obstructive airway diseases and higher BMI could be the causes of limitation of airflow in our subjects.
Possibilities of using car enamel waste in the production of iron casting
Authors:   Nizhny Novgorod State Technical University (Nizhny Novgorod Russia), Leushin I. O. , Makarov V. S. ,   Nizhny Novgorod State Technical University (Nizhny Novgorod Russia), Leushina L. I. ,   Nizhny Novgorod State Technical University (Nizhny Novgorod Russia), Geiko M. A. ,   Nizhny Novgorod State Technical University (Nizhny Novgorod Russia)
Published: December 2020

In the context of the general problem of utilization and recycling of industrial waste, the authors considered the possibility of using two types of waste of paint and varnish products of the GAZ Group of Companies — ML-12 and ML-1110 car enamels in the production of cast iron castings. Both materials are non-viscous liquid — a suspension of pigments in a solution of alkyd and melamine-formaldehyde resins in organic solvents with the addition of a solvent. The annual output of each type of waste at the base enterprise exceeds 500 tons. It was revealed that the solvent, xylene, butanol, as well as butyl acetate and white spirit, present in the composition of both types of waste and having a total share of more than 50%, are flammable liquids of organic nature with properties of solvents with a mass density lower than the density of water. Carboncontaining substances and titanium dioxide were found in the composition of the car enamel pigment. The complex of physical and operational properties of auto enamels generally meets the requirements for parting coatings and foundry paints used in the production of cast iron castings. The prerequisites for conducting assessments and making a technical decision are described in detail, the results of the program implementation are analyzed. An experimental test of the operability of the selected options for the use of waste materials was carried out in conditions of the existing production. The studies carried out have confirmed the feasibility of assessing the potential of industrial waste for recycling, which makes it possible to reduce the volume of consumed primary materials, reduce the cost of production and the environmental burden. It was recommended the enterprise to consider the possibility of using waste of ML-12 and ML-1110 auto enamels as a parting coating for foundry metal models, and use the waste of ML-12 auto enamel for painting casting molds in the production of iron casting.
Methodology for managing quality indicators of hardware products with elements of robust design
Authors:   Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia), Pivovarova K. G. , Korchunov A. G. ,   Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia)
Published: December 2020

Production of metalware is characterized with a great variety of shapes and sizes, originality of each product and a multiple-stage process. Various techniques used to process steel sections (such as cold and hot forming, machining, heat treatment, etc.) make it significantly more difficult to tackle product quality problems. Modern product quality management methodologies are based on a wide use of economical, organizational, technical and other methods. This paper describes a production-related quality control method involving certain elements of robust design. This method is based on the definition of noise factors and control parameters, as well as the conduction of noise and principal experiments. The noise experiment will help estimate the impact of disturbing factors (environmental or industrial) on product quality indicators, whereas the principal experiment will help identify the optimum production mode that can deliver the best quality and, at the same time, minimize the production losses. Robust design techniques can be effectively utilized to control the quality of metalware when developing new and optimizing the existing processes. The paper gives an example of how the quality of S10S steel bars can be controlled through the application of efficient production modes enabling to minimize quality-related costs.
Effect of modes of patenting carbon wire on its properties
Authors:   Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia), Mezin I. Yu. , Limarev A. S. ,   Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia), Salganik V. M. ,   Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia), Gun I. G. ,   Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia)
Published: December 2020

To increase the competitiveness of carbon steel grades in enterprises, it is necessary to constantly improve the production process. The manufacture of high-strength wire is an urgent area for the enterprises of the hardware industry. One of the most important indicators determining the quality of the wire is the achievement of the specified physical and mechanical properties and microstructure. To this end, the wire is subjected to patenting, which is carried out in special units. To achieve the desired result during patenting, it is necessary to choose and observe the correct regimes depending on the diameter of the wire being processed and the chemical composition of the steel. When developing the modes, it is taken into account that martensite and a significant amount of excess ferrite along the grain boundaries are not allowed in the structure of patented steel. In the course of the work, an analysis was made of the most common carbon wire patenting modes in production, statistical dependences of the designated heating modes of the wire billet and cooling medium on the parameters of the steel wire, namely, its diameter and carbon content in steel, were obtained. An assessment of its strength properties is also carried out. According to the results of the analysis of patenting modes, it was found that certain difficulties arise when mastering the process of patenting steel wires of thick diameters and a carbon content of more than 0.8. Therefore, the solution of issues related to the course of these processes seems to be an urgent task. The results of the studies show the possibility of ensuring the necessary level of mechanical properties of steel in billets of thick diameters during the implementation of the process using lead melt. The data obtained can serve as a starting point for industrial testing and the prospective development of patenting processes.
Experimental study of the error in the height of the contour of box-shaped parts, obtained by drawing from welded blanks of different thickness
Authors:   Kaluga branch of the Bauman Moscow State Technical University (Kaluga, Russia), Malyshev A. N. , Bysov S. A. ,   Kaluga branch of the Bauman Moscow State Technical University (Kaluga, Russia), Orlik A. G. ,   Kaluga branch of the Bauman Moscow State Technical University (Kaluga, Russia), Bessmertnaya Yu. V. ,   Tula State University (Tula, Ruissia)
Published: December 2020

The development of sheet-stamping production within the framework of meeting the needs of modern mechanical engineering involves the use of advanced technologies, materials and blanks, which makes certain requirements for the level of blank production technologies in general. In modern conditions, sheet-stamping production involves the manufacture of stamped parts in limited quantities due to their constantly changing design, which, in turn, requires optimization of the volume of investments and reduction of the time required for the implementation of technological preparation of production, flexibility of technological and design solutions, as well as the maximum approximation of all parameters of stamped parts to parameters of the finished product in order to reduce subsequent processing. Box-shaped sheet metal stamped parts obtained during the implementation of the drawing operation are actively used in the medical, light, watchmaking, food machine-building, electrical, instrument-making, and automotive industries. One of the main tasks for obtaining high-quality box-shaped sheet-stamped parts is the creation of a stamping technology that meets modern production requirements based on progressive methods for calculating shaping operations, as well as designing the contour of the original blank taking into account the peculiarities of the shaping process and the required geometric parameters of parts. Depending on the purpose of the box-shaped sheet-stamped part, the main geometric parameters are determined, the correspondence of the actual values of which to the required ones allows to make a conclusion regarding the quality of the obtained stamped product. As a rule, such a parameter is the height of the box-shaped part, the error of which ultimately should not exceed the tolerance assigned by the designer. For example, in the automotive industry, one of the promising directions for reducing the weight of a car while maintaining the strength parameters of its units and elements, as well as reducing their cost, is the introduction of sheet welded blanks of different thickness. This article is devoted to an experimental study of the error in the height of the contour of tall boxes with relatively large radii of corner curvatures, obtained by drawing from these blanks made of high-strength steel. This work was carried out within the framework of the grant NSh-2601.2020.8.
Influence of dispersed particles of tungsten carbide on the microstructure of 12Kh18N10T steel obtained by centrifugal casting
Authors:   South Ural State University (Chelyabinsk, Russia), Chumanov I. V. , Anikeev A. N. ,   South Ural State University (Chelyabinsk, Russia), Zherebtsov D. A. ,   South Ural State University (Chelyabinsk, Russia)
Published: December 2020

The development of new technologies in various industries, such as fast neuron reactors, require a new level of operational properties from steels and raise the issues of resistance to neutron radiation, radiation swelling, embrittlement and creep, and the level of residual activation. The principal way to increase these properties is to adjust the chemical composition, and rearrange the crystal structure of the metal. The authors propose to achieve this by introducing finely dispersed particles into the melt and controlled by them to “reinforce” the crystal lattice, grinding the metal structure. During the work, using the FactSage software package, thermodynamic modeling of the interaction of dispersed particles with a 18Х18Н10T steel melt was carried out, showing that the particles will interact with the metal melt, which can lead to their complete dissociation, and at the next stage of crystallization, regardless of the degree of dissolution of tungsten carbide, the formation of carbide phases based on titanium carbide with an FSS structure, as well as a carbide phase based on chromium carbide with the formula M23C3, will become. According to the simulation parameters, experiments were conducted, experimental blanks with different contents of the introduced tungsten carbide were obtained, and heat treatment was carried out. The study of microstructures showed that the introduced particles of tungsten carbide completely dissociate when interacting with a metal melt and contribute to an increase in ferrite in the microstructure of the workpiece. Studies of microhardness confi rmed the significant effect of the introduced carbide on the properties of the material: the maximum values of microhardness are achieved at a high concentration of refractory particles in the areas of their maximum concentration (outer edge of the workpieces). Carrying out heat treatment reduces microhardness, while aligning the gradient of properties with the volume of castings. This work was financially supported by the Ministry of Science and Higher Education of the Russian Federation within the framework of the federal target program under Agreement No. 075-15-2019-1711 (internal number 05.608.21.0276) dated December 04, 2019 (unique project identifier RFMEFI60819X0276).
Improving the quality of concentrates of Stoilensky GOK JSC with the use of magneticAgravity separation
Authors:   Belgorod State National Research University (Belgorod, Russia), Gzogyan S. R. , Scherbakov A. V. ,   JSC «Stoilensky GOK» (Stary Oskol, Russia)
Published: December 2020

An innovative high-grade magnetite concentrates production technology has been developed and pilot tested for ferruginous quartzites of the Kursk Magnetic Anomaly. This paper assesses the possibility of using magnetic-gravity separation to obtain high-grade products, suitable for direct metallization, from finely disseminated ferruginous quartzites of the KMA. The results of pilot tests are presented for the current production of high-grade magnetite concentrates from commercial concentrates and for the production of pellets at the Stoilensky GOK, which may be used to draw the following conclusions. Commercial magnetite concentrate may be processed by magnetic-gravity separation. The grade improvement (mass fraction of Fetot) in the pilot tests averaged 1.23 %, while the expected grade increase for industrial MG separation is 1.17 %. Magnetite concentrate for pellet production may also be processed by MG separation. The grade improvement in the pilot tests averaged 1.26 %, while the expected grade increase for industrial MG separation is 1.20 %. Magnetite concentrates are diluted with classes of over 0.045 mm. It is recommended to conduct the tests using classified feed. The processing of MG separation overflows, ground to d80 0.045 mm (the size of stage III industrial grinding), demonstrated the lack of prospects for obtaining any commercial product from this product.
Mechanochemical technology for obtaining an effective filler based on gaize for cement binders
Authors:   Yuri Gagarin State Technical University of Saratov (Saratov, Russia), Shoshin E. A. , Strokova V. V. ,   Belgorod State Technological University named after V. G. Shukhov (Belgorod, Russia)
Published: December 2020

The article presents a study to establish the possibility of obtaining polymodal silicate dispersions (SCD) based on common natural silicacontaining raw materials (gaize) and of using such dispersions as fillers and additives for cement compositions and assesses their effectiveness. Gaize, construction quicklime, and sucrose were used as modifying carbohydrates and silica-containing raw materials for the mechanochemical synthesis. The SCD technology includes the stages of raw material dosing, combination, and wet grinding in a ball mill, separation of the solid phase of the suspension by filtration (in drum or pressure filters) and its thermolysis in a thermolysis chamber, followed by short-term dry grinding of the thermolysis products in batch or continuous mills. The results are presented for the analysis of silicate-calcium dispersions with various ratios of the initial components. The efficiency of using SCD as a component in a composite binder or a finely dispersed mineral additive in cement-sand composites is demonstrated, which introduces mechanochemical synthesis of calcium silicates as a promising technology for processing gaize into effective fillers and additives for construction purposes. The study was carried out under the grant issued by the Russian Science Foundation (project No. 19-19-00263).
Application of mechanical activation to obtain target products in fused periclase and slags processing
Authors:   Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia), Garkavi M. S. , Orekhova N. N. ,   Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia), Gorlova O. E. ,   Nosov Magnitogorsk State Technical University (Magnitogorsk, Russia), Kolodezhnaya E. V. ,   Institute of Problems of Integrated Development of Mineral Resources of RAS (Moscow, Russia)
Published: December 2020

The article presents the results for obtaining the conditioned target product from metallurgical waste, such as vanadium-containing converter slag, steelmaking slag and magnesium-containing fused periclase, by increasing their particle surface reactivity through mechanical activation at the grinding stage. The paper presents the characteristics of the feed and grinding products and the process flows for the processing of respective technogenic raw materials. The dispersion and reactivity of the finely dispersed product, established by the change in the material wetting heat, and the role of mechanical activation for the subsequent processing and improvement of the resulting product grade are evaluated. Mechanical activation of magnesium oxide powder at the last processing stage for low-grade fused periclase promotes an increase in the energy of surface-active centers of the ground material and an improvement in its electrical insulating properties (as compared with ball grinding). Mechanochemical activation of vanadium slag promotes the formation of homogeneous, well-permeable granules, intensification of redox processes during leaching and obtaining the target product (V2O5 paste) with the mass fraction of vanadium pentoxide of 84–86 %. An increase in the reactivity of the dump steelmaking slag during mechanochemical activation allows obtaining high-activity composite cements with the slag content of up to 20 wt.%.