bluuebunny/crossref_metadata_2025 huggingface dataset:
Gefügeentwicklung durch Wärmebehandlung an Magnesiumlötverbindungen
Authors: Wielage Bernhard , Mücklich Silke
Published: March 2022

Kurzfassung

Lötverbindungen mit Zn-Mg-Al-Loten an Magnesiumgrundwerkstoffen bilden in Abhängigkeit vom Grundwerkstoff und von der eingesetzten Lotlegierung sehr unterschiedliche Gefüge aus. Wie bereits in [1] beschrieben, kommt es bei Einsatz binärer Mg-Zn-Lote zu der Beobachtung, dass das Lot bedingt durch die beschleunigte Abkühlung während des Lötvorganges kein feinlamellares eutektisches Gefüge ausbildet, sondern in einem Gemisch mikrokristalliner, intermetallischer Phasen erstarrt. Da sich diese Morphologie negativ auf die mechanischen Eigenschaften auswirkt, wird versucht, durch eine nachgeschaltete Wärmebehandlung eine günstigere Gefügeausbildung zu erzielen.
Einfluss von thermomechanischer Behandlung auf die Mikrostruktur von pseudoelastischem NiTi am Beispiel von Komponenten für Brillengestelle
Authors: Frotscher M. , Menges C. , Diehl O. Th. , Eggeler G.
Published: March 2022

Kurzfassung

Eines der in der Literatur am häufigsten aufgeführten Anwendungsbeispiele für Nickel-Titan-Formgedächtnislegierungen (NiTi-FGL) sind Komponenten für Brillengestelle [1, 2, 3]. Dabei werden insbesondere die Nasen- und Seitenbügel, sowie Verbindungselemente aus diesem Werkstoff hergestellt [4, 5, 6]. Für den Nutzer hat dies den großen Vorteil einer erhöhten Flexibilität bei erzwungener Verformung zum Beispiel beim Verbiegen oder Herunterfallen der Brille. Im Rahmen der vorliegenden Arbeit wurden Brillenkomponenten verschiedener Hersteller aus NiTi mit Hilfe von rasterelektronenmikroskopischen Methoden untersucht. Die Proben wurden dabei verschiedenen thermomechanischen Behandlungen unterzogen, um deren Auswirkung auf die Mikrostruktur und sowie auf die funktionellen und strukturellen Eigenschaften zu charakterisieren.
TEM Study of Bainitic Low-Carbon HSLA Steel: The Orientation Relationships of Cementite
Authors: Illescas Silvia , Fernández Javier , Asensio Juan , Guilemany Josep Maria
Published: March 2022

Two different bainitic structures can be present in steel depending on the heat treatment to which the samples are subjected. The two different types of bainitic structures exhibit a different orientation relationship between the cementite and the ferrite matrix. The Pitsch orientation relationship is observed in upper bainite while the Bagaryatski orientation relationship is observed in lower bainite [1]. Different heat treatment samples of low-carbon High Strength Low Alloy (HSLA) steel were studied using TEM observations in order to ascertain the orientation relationship between ferrite and carbide in the different bainitic structures and to determine whether this relationship may indicate the type of bainitic structure.
Electrical conductivity and thermal stability of surface-modified multiwalled carbon nanotubes/polysulfone/poly(p-phenylenediamine) composites
Authors: Abdelhamid Ahmed E. , Ward Azza A. , Khalil Ahmed M.
Published: March 2022

Multiwalled carbon nanotubes (MWCNTs) were functionalized with acid then coated with poly(p-phenylenediamine) (PpPD). Various concentrations of modified multiwalled carbon nanotubes (MWCNTs@PpPD) were introduced to a polysulfone (PSU) and poly(p-phenylenediamine) (PpPD) blend providing nanocomposites in form of sheets. Chemical oxidative polymerization was used to polymerize p-phenylenediamine. PpPD is then applied as a compatibilizer in such heterogeneous system to facilitate a successful percolation for MWCNTs in the polymeric matrix as an enhanced conductive filler. The morphological investigations showed homogeneous distribution for MWCNTs in the polymeric matrix. The prepared composites were investigated demonstrating favorable thermal and electrical properties. Thermogravimetric analysis (TGA) emphasized that MWCNTs@PpPD contributed in enhancing the thermal stability of the prepared sheets. The electrical conductivity of PSU/PpPD/MWCNTs@PpPD nanocomposites boosted upon raising the magnitude of loaded MWCNTs. The existence of MWCNTs@PpPD in the polymeric matrix extended the interfacial polarization effects with elevating the conductance. The loaded composite with (7.5 wt%) MWCNTs@PpPD showed the optimum electrical conductivity values. It was then treated with HCl to protonate the amine groups in PpPD showing higher conductivity value than its corresponding untreated one. PpPD and MWCNTs contributed synergistically in modifying the insulation feature of PSU to a favorable electrical conductivity one.
Influence of hydrothermal aging on the mechanical performance of foam core sandwich panels subjected to low-velocity impact
Authors: Liu Youping , Wu Ye
Published: March 2022

The effect of hydrothermal aging on the impact resistance of foam core sandwich panels is studied in this study. The sandwich panels with glass fiber-reinforced skins and polyurethane foam core were fabricated and then were treated with different hydrothermal aging conditions. The moisture absorption characteristic of the composite skins was evaluated. A modified Fickian formulation was proposed to predict the moisture absorption behavior of composite skins. The low-velocity impact resistance of the aged sandwich panels was determined at three different impact energies. The impact responses including contact force, deflection, and dissipated energy of the sandwich panels with and without hydrothermal aging were analyzed. The macroscopic and microscopic damage morphologies were observed by visual inspection and scanning electron microscope methods, respectively. The damage mechanism of the aged panels was revealed. Results indicate that the impact resistance of aged sandwich panels is degraded, and the performance degradation is larger with increasing aging temperature. Compared to the panel without hydrothermal aging, the reduction of the contact force is 35.69%, and the increase of the deflection is 71.43% for the aged panel at 70°C aging temperature. The fiber/matrix interfacial cohesive performance is degraded resulting from the hydrothermal aging.
Technologiemanagement – ein Kernprozess für Unternehmen
Authors: Schuh Günther , Klappert Sascha , Moll Torsten
Published: March 2022

Die Schnelllebigkeit von Technologien ist häufig der Grund dafür, dass Unternehmen neue Technologien nicht rechtzeitig erkennen oder einführen. Doch gerade die Identifikation neuster Technologien und das frühzeitige Erkennen daraus resultierender Chancen sichert in der Konsequenz den langfristigen Unternehmenserfolg. Eine systematisch betriebene Technologiefrüherkennung und die Verwendung von geeigneten Werkzeugen, wie zum Beispiel der Technologiroadmap, sind hier entsprechende Ansätze des Technologiemanagements, die in der unternehmerischen Praxis etabliert werden müssen. In diesem Artikel wird beschrieben, wie die Aufgaben der Technologiefrüherkennung mit geeigneten Hilfsmitteln im Unternehmen auch über verschiedene Bereiche hinweg verankert werden können, um dadurch das Fundament für ein erfolgreiches Technologiemanagement zu legen. Hierbei steht als zentrale Herausforderung auch die Bündelung der Aktivitäten des Technologiemanagements durch die Integration verschiedener Abteilungen und Unternehmensbereiche im Fokus der Betrachtung.
Kompetenzzellenbasierte Optimierung von Werkstattstrukturen hilft Kosten senken
Authors: Strunz Matthias , Nobis Senftenberg, Thomas
Published: March 2022

In Zukunft werden Unternehmen zunehmend ihre Ressourcen in Form von eigenständig lebensfähigen Kompetenzzellen bereitstellen. In diesem Artikel wird hierzu ein Ansatz vorgestellt, der die optimale Gestaltung von sensiblen Dienstleistungsstrukturen in Unternehmen in der frühen Planungsphase zum Ziel hat, um das Investitionsrisiko zu verringern. Auf der Basis des Leistungsprogramms von Serviceunternehmen generiert der Planer Kompetenzzellen, die miteinander funktions- und/oder prozessorientiert vernetzt werden können. Der Einsatz digitaler Visualisierungssysteme, die den Planungsprozess, beginnend bei der Projektidee über die Planung und Vorbereitung bis zu deren Umsetzung in funktionsfähige Kompetenzzellen und deren Vernetzung wesentlich unterstützen und verkürzen, wird an einem praktischen Beispiel dargestellt.
Integriertes Abzugssystem für das Weben von Spacer Preforms für textilverstärkte Verbund-Bauteile
Authors: Großmann Knut , Mühl Andreas , Löser Michael , Holowenko Olaf , Möbius Volker
Published: March 2022

Für das Heißpressen hohlraumbehafteter, textilverstärkter thermoplastischer Verbund-Bauteile werden textile Preforms benötigt. Am SFB 639 der TU Dresden wird der Prozessketten verkürzende Ansatz verfolgt, diese Preforms aus Hybridgarnen, die die Verstärkungsfaser und die Matrix-Komponente bereits enthalten, endformnah als Spacer Fabrics webtechnisch herzustellen. Im ersten Teil des Beitrags wurden das Konzept und die Konstruktion dieses integrierten Abzugssystems behandelt. Der zweite Teil beschreibt zuerst ein entwicklungsbegleitend einsetzbares Simulationsmodell zur Berechnung der dynamischen Wechselwirkungen zwischen Webmaschine sowie Abzugs- und Fadensystem. Anschließend wird für die Anlage die funktionale Systemstruktur abgeleitet und die darauf aufbauende Steuerungsentwicklung dargestellt. Die Beschreibung eines Emulators, mit dessen Hilfe die Steuerungsinbetriebnahme unterstützt wird, beschließt den Artikel.*
A Qualitative Investigation into the Lived Experiences of Critical Care Nurses Working on Night Shifts
Authors:   Department of Nursing, College of Nursing, Hawler Medical University, Erbil, Iraq., Rasheed Halmat , Aziz Newroz ,   Department of Nursing, College of Nursing, Hawler Medical University, Erbil, Iraq., Osman Goran ,   Department of Nursing, College of Nursing, Hawler Medical University, Erbil, Iraq.
Published: March 2022

Background and objectives: Shift work is used in the hospitals and residential treatment centres to provide patients with continuous health care. During their night shift, nurses are often faced with different health problems either due to the stressful work environment or because of the sophisticated instruments to be utilized in intensive care units. The present study was aimed at investigating the lived experience of nurses working on the night shifts at Rizgary Teaching Hospital located in Erbil, Iraqi Kurdistan Region. Methods: A qualitative phenomenological study was conducted to describe the lived experiences of nurses working on night shifts. In doing so and in order to collect the required data, open-ended semi-structured in-depth interviews were carried out to explore thoughts, feelings, and lived experiences of 15 nurses who were working on the night shifts in the Intensive Care Unit (ICU) at Rizgary Teaching Hospital in Erbil. The collected data were then analyzed by Van Manen’s (1990) method. Results: Study participants were between 26 and 38 years old. The majority were male (60%) and 40% were female. Regarding marital status, 10 participants were married and 5 were single. Most of the nurses had Bachelor degrees (86.6%). The respondents work experience was between 3 and 8 years. Almost all of the participating nurses had similar lived experiences during their night shifts. The nurses' lived experiences gave way to the emergence of four themes namely workload, psychosocial issues, sleep disturbance and physiological issues. Conclusion: The present study showed that nurses working on night shifts faced many problems and issues such as poor sleep quality sleep, working for a long time, fatigue and anxiety, back pain, mood disturbance and lack of concentration.
Nurses’ Awareness toward Risk Factors of Breast Cancer in Kirkuk City Hospitals
Authors:   Department of Nursing, College of Nursing, Sulaimani University, Sulamani, Iraq., Saadoon Burhan , Abdulla Salih ,   Department of Nursing, College of Nursing, Hawler Medical University, Erbil, Iraq.
Published: March 2022

Background and objectives: In women worldwide, breast cancer is the most common can-cer. It is one of the leading causes of cancer death in women, accounting for 15% of all cancer deaths in the female population. In most countries, breast cancer incidence rates are higher than they have ever been at an early age. This study aimed to identify the level of nurses’ awareness towards risk factors of breast cancer. Methods: A cross-sectional study was carried out among 341 nurses from different de-partments in three Kirkuk city hospitals (Azadi Teaching Hospital, Kirkuk General Hospital, and Pediatric Hospital) from 25 February to 25 June 2021. A non-probability/convenient sampling technique was utilized to collect data. A socio-demographic characteristics data form and awareness of breast cancer risk factors form were used to collect data through face-to-face interviews. Data were analyzed using Statistical Package for the Social Scienc-es, version 21, presenting descriptive and inferential statistics comprising frequency, per-centage and chi-square test. Results: Out of the 341 nurses, 44.9% were from Azadi Teaching Hospital, while more than one-third (38.1%) were from Kirkuk General Hospital, and 17% were from Pediatric Hospi-tal. Most of the nurses, 38.4%, were between the ages of 21 and 25, 64.8% were female, and 66.9% were married. About 36.1% of nurses report acceptable level of awareness and 5.9% report being with good level of awareness about risk factors associated with breast cancer. Conclusion: The awareness level of breast cancer risk factors among nurses working in Kirkuk city hospitals was generally high. Younger age was associated with higher level of awareness of risk factors. Regarding to the gender was highly significant differences be-tween the nurses’ awareness of breast cancer risk factors.
Development of a model for increasing the level of skilled digital technologies in the conditions of personalization of educational trajectories of pupils
Authors:   Novosibirsk State Pedagogical University, Kamenev Roman Vladimirovich , Stupina Elena Evgenievna ,   Novosibirsk State Pedagogical University, Stupin Andrey Anatolyevich ,   Novosibirsk State Pedagogical University, Klassov Alexander Borisovich ,   Novosibirsk State Pedagogical University, Sartakov Igor Vitalievich ,   Novosibirsk State Pedagogical University
Published: March 2022

The article discusses the issue of mastering end-to-end digital technologies by schoolchildren. The authors analyze the conditions for personalizing the educational trajectories of schoolchildren, which are necessary for mastering end-to-end digital technologies. All elements of the model for increasing the level of proficiency in end-to-end digital technologies are considered: the didactic goal, the content of training, methods and forms of organizing the educational process. The purpose of the article is to present the model developed by the authors for increasing the level of proficiency in end-to-end digital technologies in the context of personalizing the educational trajectories of schoolchildren, to prove its effectiveness. Research methodology and methods. The research methodology is based on a comparative and comparative analysis of the results of experimental work on the implementation of the model in the educational process of an educational organization. Research results, discussion. Comparative analysis of the results of experimental work on the implementation of the model in the educational process of an educational organization showed a significant increase in the level of proficiency in end-to-end digital technologies after the introduction of the model into the educational process of an educational organization. Conclusion. The prospects of the obtained presented data are associated with solving the problem of increasing the level of proficiency in end-to-end digital technologies in the context of personalizing the educational trajectories of schoolchildren. For teachers of schools, centers of additional education working in a digital educational environment, it is necessary to take into account in their work special conditions and principles to increase the level of proficiency in end-to-end digital technologies.
Pedagogical act as a means of manifestation and formation of moral and value independence of future teachers
Authors:   Irkutsk State University, Golubchikova Marina Gennadievna
Published: March 2022

The article presents the author’s view on the importance of a pedagogical act for the formation of correct moral behavior in the process of training future teachers and in professional activity. The term “morally valuable independence” is considered as a characteristic of the result of upbringing and self-education of future teachers. A method of forming moral and value independence through preparation for a pedagogical act through case technology is proposed. The purpose of the article is to reveal the possibilities of pedagogical action as a means of manifestation and formation of moral and value independence of students – future teachers. Methodology and methods of research: the methodological basis of the research is a competence-based approach to pedagogical education; in the process of research, theoretical methods were used – analysis of scientific sources; logical – analysis, synthesis, systematization, generalization; diagnostic – questionnaires, testing; methods of quantitative and qualitative analysis of the results obtained. Research results, discussion. As the study showed, by the end of the experiment, a considerable part of the students showed the ability to creatively, non-standard analysis of pedagogical situations based on moral values, which indicates readiness for pedagogical action. Thus, in the process of solving pedagogical tasks aimed at the formation of readiness for action, there is a formation of moral and value independence of future teachers Conclusion. Preparation for the performance of a pedagogical act on the basis of case technology allows solving a number of tasks relevant for the development of moral qualities: maximally activate each student, involve him in the process of analyzing the pedagogical situation and making the right decision; promote the effective application of theoretical knowledge in pedagogical activity to predict possible consequences. This is facilitated by the use of developed orientation schemes in the learning process, which are a support for students in working with pedagogical situations.
Integrating online Teaching English into the system of higher education
Authors:   Pskov Branch of the Academy of Federal Penal Service of Russia, Ivanova Natalia Nickolaevna
Published: March 2022

The article discusses current problems in organizing and conducting online classes. The effectiveness and compliance of online teaching English with the modern competence approach in the process of evaluation of effectiveness of the selected learning model. The purpose of the article is to justify effectiveness of managing the student’s learning activities in the process of online learning through an optimal combination of possibilities of Moodle electronic educational environment and the use of interactive pedagogical technologies. Methodology and methods of research. The study was conducted on the basis of the implementation of the model of online English course as a process of building up students’ professionally significant competencies, development of students’ self-regulation strategies and improvement of their soft skills and abilities. The research methods used were the analysis of pedagogical, socio-psychological, scientific-methodological and special professional literature on the problem of research; purposeful observation of the process of development and training of students, analysis of experimental data, questionnaires. The developed model of online English course was implemented as part of an experimental study of the discipline “The English Language”. Conclusion. It is worth noting that the implementation of online teaching model based on the concepts of Edutainment, Self-Regulative Strategies of learning, as well as communicative approach with the use of interactive pedagogical technologies integrated into content-based learning corresponds to the modern competence-based approach implemented in the educational process of the discipline “The English Language”.
Mechanisms for Analysis of Educational and Professional Motivation of Speech Therapists Students
Authors:   Saratov National Research State University named after N. G. Chernyshevsky, Bochkareva Tatyana Anatolyevna , Kryuchkov Vladimir Petrovich ,   Saratov National Research State University named after N. G. Chernyshevsky, Rudzinskaya Tanzilya Faatovna ,   Saratov National Research State University named after N. G. Chernyshevsky
Published: March 2022

The relevance of the study is due to the need to improve the training system for teaching staff, including speech therapists. The goal is to develop mechanisms of a structural and functional analytical pedagogical model for studying the educational and professional motivation of bachelor students of the “Speech therapy” profile. Tasks – defining the concept of the model, its levels, the approximate content of each level, testing the model in practice. The result is the substantiation of the concept of an analytical model for studying the educational and professional motivation of speech therapists, its level organization, creating its basis: disclosing the content of the organizational and technological, formal, meaningful, interpretive and predictive levels, as well as its approbation in the course of studying educational and professional motivation students of the profile “Speech therapy” of the Faculty of Psychological, Pedagogical and Special Education, SSU named after N. G. Chernyshevsky. The latter showed the effectiveness of the developed model in terms of identifying the dynamics of educational and motivational processes and factors affecting educational and professional motivation.
“RELIGIOUS FEELING” IN THE SHORT NOVEL (POVEST') BY V. F. ODOEVSKY “THE UNSPENT HOUSE”
Authors: Tereshkina Daria
Published: March 2022

The article offers an analysis of V. F. Odoevsky's short novel (povest’) “The Unspent House” (1840) in the context of its reflection of the “religious feeling” that was characteristic of writer-encyclopedist V. F. Odoevsky throughout his life. In the “The Unspent House”, which combines the traditions of a romantic short novel (povest’) with elements of fiction, ancient Russian legend, hagiographical texts, apocrypha, spiritual verse, “religious feeling” is manifested not only in the syncretic poetics of the work, where the gospel text sounds most clearly, but also at the level of understanding Christianity as a nationwide “religious feeling” with the most diverse connotations, but with the general meaning of forgiveness, mercy and love. The spiritual poems, whose publication V. F. Odoevsky later actively participated in, were the likely sources of the short novel (povest’). Works of medieval literature (“The Walk of the Virgin in Torment”, “The Tale of Savva Grudtsyn”) may have been the sources of the “legend”; parallels are also found with hagiographic literature. The “religious feeling” of V. F. Odoevsky, as stated in the article, intended to unite different layers of the Russian Christian culture. It asserted “joyful Christianity,” which was characteristic of book culture and oral folk art, and based on the belief in the power of mercy, compassion for sinners and the ultimate salvation of the soul.
Optimization of schedules for early garbage collection and disposal in the megapolis
Authors: Saukenova Indira , Oliskevych Myroslav , Taran Igor , Toktamyssova Aliya , Aliakbarkyzy Dana , Pelo Roman
Published: March 2022

It is shown that due to the growth of waste generated by the metropolis, the processes of their removal and disposal must be more accurately accounted and controlled. If it is impossible to introduce “smart” control systems, it is proposed to search for reserves to increase the efficiency of the processes in their structure. A structural model of operations has been developed that can reduce time costs. The use of incomplete information on the accumulation and removal of garbage leads to unplanned mileage of trucks. In order to avoid unforeseen costs, it is proposed to use early garbage collection, which reduces the frequency of emptying containers. This leads to an increase in the number of truck arrivals to load, but eliminates unforeseen mileage due to inconsistencies in the loading forecast. It is shown that to effectively organize the work of garbage trucks on the transport network of the city, an active, shortest schedule of operations is required, which must be made for several periods. To develop an optimal cyclic schedule of garbage trucks, a method based on the ordering of mixed graphs is proposed. The mixed graph shows the set of garbage collection operations and the time relationships between their execution times. In order to develop an optimal schedule from such a graph, cycles must be removed from the graph. To do this, the “divide and conquer” method was used. The proposed algorithm for graph ordering is used to study the current garbage collection system. As a result of research, higher productivity of garbage trucks and timely removal of organic waste were achieved. The reduction of the weekly working time of 6 garbage trucks with the use of the 70 % container filling level reached 42 hours.
Designing a toolset for the formalized evaluation and selection of reengineering projects to be implemented at an enterprise
Authors: Chupryna Iurii , Ryzhakova Galyna , Chupryna Khrystyna , Biloshchytskyi Andrii , Tormosov Ruslan , Gonchar Viktoriya
Published: March 2022

The innovative content of the components, stages, and results of the construction and implementation of the toolset, which provides a formalized assessment and choice of a rational scenario for reengineering implementation at a modern enterprise in the form of a target project, was displayed. The need for research is caused by the fact that the existing approaches to reengineering business processes in an application for construction enterprises require significant adjustments. The reengineering of a construction enterprise as a target project should be coordinated with the projects and works executed by a construction enterprise.
The proposed analytical support makes it possible to determine for each of the construction enterprises an alternative to reengineering adapted for its needs. Modules as part of the proposed analytical support implement a single algorithm of unambiguously formalized substantiation of the construction enterprise renovation project – through a developer reengineering project. This toolset allows rationalizing and adjusting decisions on the coordination of determinative characteristics of the above project – the essence of changes, their duration, estimated cost, investment stages.
The presented study provides a clearly formalized management technology for evaluating and selecting reengineering options, determining in advance the future benefits of reengineering transformations, namely, functional-technological, technological, technical, managerial, and economic changes. The created analytical support makes it possible to perform successful administrative support of a reengineering project. Its implementation will ensure an irreversible qualitative "jump" in the trajectory of the life cycle of an enterprise and expected strategic priorities.
Construction of algorithms for solving the inverse problem when using indicators in several calculation functions
Authors: Gribanova Ekaterina
Published: March 2022

This paper reports a solution to the inverse problem when using indicators in several calculation functions. Such problems arise during the formation of a multi-level scorecard; solving them makes it possible to determine the value of arguments in order to achieve the specified value of the resulting indicator of each level. Thus, the characteristics of an economic object can be defined in order to achieve the specified indicators of its functioning. Optimization models are given in the presence of various types of conditions for achieving the result. In contrast to existing methods, the approach based on building nonlinear programming models makes it possible to solve the inverse problem for the case where several indicators are used in different calculation functions. Algorithms for solving the inverse problem have been constructed, involving the transformation of constraints and the use of an iterative procedure based on inverse calculations. For the case of using coefficients of relative importance, two techniques of solving the problem have been considered: the formation of a single model for subtasks and the adjustment of the solution to subtasks while minimizing the sum of squares of argument changes. In comparison with the existing method, the proposed algorithms have made it possible to derive a solution with a greater correspondence of the changes in the arguments to the coefficients of relative importance. A solution to the inverse problem has been considered related to the formation of marginal profit of an enterprise in the presence of two points of sale and three types of products, as well as the joint formation of revenue and cost. The results of this study could prove useful to specialists in the field of decision-making in the economy and to developers of software decision support systems that include functions for solving inverse and optimization problems.
Determination of optimal size and location of static synchronous compensator for power system bus voltage improvement and loss reduction using whale optimization algorithm
Authors: Rasool Ali Abdulqadir , Abbas Najimaldin M. , Sheikhyounis Kamal
Published: March 2022

Power systems are usually expected to become heavily loaded as the demand for electrical energy grows and economic consideration limits the installation of additional transmission and generating capacity. Keeping the bus voltage in the power system within the standard permissible limits is an important concern to improve the voltage stability and avoid voltage collapse of the whole power system. The common and effective way to achieve this purpose is by adding flexible AC transmission line devices to the power system. One of these devices is static synchronous compensator. In this paper an approach is proposed to find optimal location and size of static synchronous compensator for improving bus voltage in the power system. A load flow is conducted to identify the low voltage buses which are the weak buses in the system and they are considered as suitable buses for static synchronous compensator connection. An objective function is formulated for optimization process which contains four parts, the voltage deviation, static synchronous compensator size, active and reactive power losses of the whole power system. Whale optimization algorithm is used for the optimization process. The proposed approach is applied on the real power system of Kurdistan Region using power system simulator for engineering software for simulating the power system and finding the optimal size and location of static synchronous compensator for bus voltage improvement. The results are encouraging for applying the approach to any power system. What distinguishes this method is that it accomplishes two things, namely reducing the bus voltage deviation to zero which means that all bus voltages are within the permissible limits and minimizing losses as well.
Determiningcarrot preservation depending on the root quality and size, as well as on storage techniques
Authors: Pusik Ludmila , Pusik Vlаdimir , Bondarenko Veronika , Gaevaya Ludmila , Kyruchina Natalja , Kuts Oleksandr , Slobodianyk Galina , Nakloka Olga
Published: March 2022

This study aimsto scientifically substantiate the influence of the quality, size of carrot roots, as well as storage techniques, on safety that couldprolong their consumption.
The research into carrot roots has not been developed properly. In this regard, it is important to conduct comprehensive studies of objective indicators that exert the greatest impact on the intensity of natural weight loss of carrot roots and their preservation. The study reported here aimed to scientifically substantiate the influence of the quality, size of carrot roots,as well as storage techniques, on safety, which could allow them to be consumed longer.
It has been theoretically substantiated and experimentally confirmed that the longest storage period of 206 days with a commercial yield of 89.27 %characterized large root crops. The output of marketable products of medium root crops was 86.56 %, small ones after 161 days ‒ 80.30 %. Compared with large root crops, the shelf life of both small and mechanically damaged carrots decreased by 46 days, and the yield of marketable products decreased by 9.0 and 11.1 %, respectively. Carrot roots damaged by pests were preserved almost the same as chopped ones. On average, over 191–192 days of storage, the yield of marketable products amounted to 83.43 and 83.90 %, respectively. The shortest shelf life (142) and the worst preservation (68.34 %)were observed in carrots with a torn peel, due to a large number of diseased root crops (18.53 and defective ones (6.85 %).
Storage of carrots in boxes at a permanent storage facility with forced-air and exhaust natural ventilation turned out to be ineffective. The yield of marketable products amounted to 85.5 %. The highest safety of 96.3–94.3 % was observed when the roots were stored in plastic bags and perforated bags, respectively. A greater yield of marketable products is provided by bags with a capacity of 5 kg. It was found that the storage in cardboard boxes and paper bags contributed to the development of microorganisms. The number of affected root crops ranged from 2.4 to 2.8 %.
Devising an approach to the geometric modeling of railroad tracks along curvilinear sections
Authors: Borisenko Valeriy , Ustenko Serhiy , Ustenko Iryna
Published: March 2022

This paper proposes an approach to arranging curvilinear sections of the railroad track, which involves the replacement of two transitional ones and a circular curve with one curvilinear section. Modeling this section implies the construction of a curve in the plan and profile, the joint consideration of which forms the spatial appearance of the curve, which ensures a smooth transition between the rectilinear rails. The need for such transitions is due to the terrain, the need to bypass settlements, and the presence of geological, geographical, and other obstacles that occur when laying railroads. A curvilinear section is modeled in the plan using a curve that is represented in natural parameterization under the law of curvature distribution in the form of a fifth-power polynomial. At the same time, at the start and end points of the section, the curvature and its derivative accept zero values. The outer rail elevation retraction (modeling in the profile) is performed using the curve built, whose sections are also represented in natural parameterization with the dependences of the curvature distribution on the arc length in the form of fourth-power polynomials. At the docking point of the sections, the third order of smoothness is ensured, which implies the equality of values of the functions, their derivatives, the curvature, and a derivative of the curvature from the length of its natural arc. Measures have been proposed to ensure the predefined track gauge retraction. The application of the proposed approach to model a railroad track along the curvilinear section with a variable-radius curve could make it possible to achieve a favorable curvature distribution, a smooth elevation retraction of the outer rail and the track gauge. That would consequently improve the safety of rolling stock running along the curvilinear section of the track, reduce the lateral and vertical efforts that predetermine the wear of rails and wheelsets.
Optimization of the control system for an electric power system operating on a constant-power hyperbole
Authors: Budashko Vitalii , Sandler Albert , Shevchenko Valerii
Published: March 2022

For an electric power system (EPS) of the combined propulsion complex (CPC), working on a constant-power hyperbola (CPH), the strategy of managing power distribution between propulsion electric motors and own needs consumers has been improved. The study reported here aimed to reduce fluctuations in current consumption and load by optimizing voltage controllers and the rotation frequency of generator assemblies (GA). The system of EPS GA voltage and frequency stabilization was synthesized by determining, in the system of equations, the dynamics of the values of EPS links' time constants and the coefficients that correspond to control parameters. To define the characteristics of the control signals from the regulators of EPS GA rotation frequency and excitation voltage, the laws that control the speed and excitation current were calculated. After sampling the coefficients of the GA speed control regulator, the tasks for the excitation voltage controller were determined. The methodology of data acquisition was applied on the basis of a correlation between the EPS characteristics and the experimental characteristics of GA. The system of EPS dynamics equations was optimized in accordance with the structure and settings of the optimal controller and the probability of a situational error by using Spearman's rank correlation coefficient. The optimization has made it possible to reduce the likelihood of a situational error during the synchronization of GA and enable the stable operation of GA close to the mode of operation on CPH. The power controller was tested under the mode of changing the load of own needs with the power levels of EPS on CPH in the range of 50‒100 % of the rated power. The range of deviations of the current consumed with an enabled GA rotation controller was 10 % of the average value. The range of EPS power deviations with the power controller turned on was 5 %.
Optimizing the partial gear ratios of the two-stage worm gearbox for minimizing total gearbox cost
Authors: Quang Nguyen Huu , Linh Nguyen Hong , Huy Trieu Quy , Lam Pham Duc , Tuan Nguyen Anh , Ngoc Nguyen Dinh , Hung Le Xuan , Pi Vu Ngoc
Published: March 2022

Optimizing the design of a worm gearbox is complex to get due to considering multiple objectives and numerous main design parameters. Hence, a more consistent and robust optimization technique will be considered in obtaining the optimized results. This paper presents the optimization process of the Two-Stage Worm Gearbox with the objective function of minimizing total gearbox cost. Ten main design parameters are chosen as input parameters for evaluating their impacts on the response of the partial gear ratio u2. In this study, the simulation experiments were used, which do not need cost to perform all potential tests. In order to do this, a 2^(10-3) model and using 1/16 fractional model were selected due to the limitation of the built-in function in Minitab@18. Moreover, the screening experiments are purposely used to determine the number of parameters, which has a minor influence on the response. Compared to using the Taguchi technique, the model of 2^11 corresponding to L32 or 32 tests is a simple method to achieve the objectives.
The results show that Total gearbox ratio exhibits the biggest effect on the response compared to others. Furthermore, the interactions between these factors to the remaining are significant. The high reliability of the proposed model is verified by simulation experiments. The random tendency of data shows that u2 is not crucially influenced by other than the input parameters. The data in versus order prove that the response is not varied to the time factor. Moreover, the coefficients of adjusted R2 and R2 are both greater than 99 %, it can be concluded that the proposed regression model is appropriate. The proposed optimization process in this study is reliable and the optimal design method can provide a useful reference on performance improvement of other worm gears.
Identification of regularities in the development of the baby economy as a component of the nanolevel of economic system
Authors: Ostapenko Tetiana , Britchenko Igor , Lošonczi Peter , Matveiev Serhii
Published: March 2022

This study has proven that the economic system is determined by various components, in particular, it includes the real sector of the economy, which is formed on mega-, macro, meso-, micro-and nano-levels. In addition, it was proved that the nano-level is determined by the activities of individuals whose economic activity begins with the birth and attitude of parents, attending various educational and upbringing institutions, and studying at university. A separate segment of the nano-level of the economic system is the baby industry responsible for the production of goods and services for children and future parents. All these aspects are indicators of the development of the baby economy. Such an economic category as the baby economy was separated and defined. The study uses the following methods: analysis, synthesis, structural analysis, systemic approach, observation, comparison, multifactor regression. These methods made it possible to achieve the results, which involve isolation of the baby economy as a component of nanoeconomy and definition of such components of the baby economic segment of nanoeconomy as a family or household economy, the baby industry, the economy of the educational process and upbringing. For this purpose, the value-institutional approach was applied. In addition, multifactorial analysis of the impact of indicators of the baby economy development on the population of a country with a transitive economy with incomes below the subsistence minimum was performed. This analysis identified a direct but minor relationship between these phenomena, which demonstrates the need to intensify and create a policy for the baby economy in similar states. The theoretical significance of the obtained results is determined by the introduction of a new economic category of "the baby economy" for the formation of a nano economic component within socio-economic systems.
Estimation of the strength of vertical cylindrical liquid storage tanks with dents in the wall
Authors: Suleimenov Ulanbator , Zhangabay Nurlan , Utelbayeva Akmaral , Azmi Murad Masrah Azrifan , Dosmakanbetova Aibarsha , Abshenov Khassen , Buganova Svetlana , Moldagaliyev Arman , Imanaliyev Kuanysh , Duissenbekov Bolat
Published: March 2022

A multi-level mathematical model was used to estimate the stressed-strained state of a cylindrical reservoir with a defect in the wall shape in the form of a dent; the concentration of stresses in the defect zone was studied.
The proper choice of the mathematical model was verified; it has been shown that the engineering assessment of the stressed-strained state of the wall of a cylindrical tank with the variable thickness could employ ratios for a cylindrical shell with a constant wall thickness. The spread of values is 2‒10 %. This indicates the proper choice of the mathematical model, as well as the fact that it is possible, for an engineering assessment of the stressed-strained state of the wall of a cylindrical tank with variable thickness, to use the ratios for a cylindrical shell with a constant wall thickness.
The stressed-strained state of the dent zone in the tank wall was numerically estimated, which proved the assumption of significant stress concentrations in the dent zone and indicated the determining effect on the concentration of stresses in the dent zone exerted by its geometric dimensions and its depth in particular.
The concentration of stresses in the zone of dents in the tank wall was investigated in the ANSYS programming environment at different sizes of dents on the tank wall, for which two dimensionless parameters were introduced: the dimensionless radius of the dent and the dimensionless depth of the dent.
Based on the results of a numerical study into the stressed-strained state of the dent zone in the tank wall, graphic dependences were derived of the stress concentration coefficient on the dimensionless depth of the dent for various values of the dimensionless radius of dents, which does not exceed 2 % of the indicator.
Based on fitting the stress concentration curves on the dimensions of the dent and tank, a formula was derived for calculating the stress concentration coefficient as a function of the dimensionless radius ξ and the dimensionless depth ς of the dent. The resulting formula makes it possible, with known dimensionless parameters of the depth and radius of the dent, to determine the coefficients of stress concentration in the dented zone of the tank wall.
Solution of one optimum control problem regarding the depletion of gas reservoir
Authors: Mamtiyev Kamil , Aliyeva Tarana , Rzayeva Ulviyye
Published: March 2022

Using the methods of the optimal control theory, the problem of determining the optimal technological mode of gas deposits’ exploitation under the condition of their depletion by a given point in time is solved. This task is of particular interest for the exploitation of offshore fields, the activity of which is limited by the service life of the field equipment. The considered problem is also of certain mathematical interest as an objective of optimal control of nonlinear systems with distributed parameters. The usefulness and importance of solving such problems are determined by the richness of the class of major tasks that have a practical result. As an optimality criterion, a quadratic functional characterizing the conditions of reservoir depletion is considered. By introducing an auxiliary boundary value problem, and taking into account the stationarity conditions for the Lagrange functions at the optimal point, a formula for the gradient of the minimized functional is obtained.
To obtain a solution to this specific optimization problem, which control function is sought in the class of a piecewise continuous and bounded function with discontinuities of the first kind, the Pontryagin’s maximum principle is subjected. The calculation of the gradient of the functional for the original and adjoint problems with partial differential equations is carried out by the method of straight lines.
The numerical solution of the problem was carried out by two methods – the method of gradient projection with a special choice of step and the method of successive approximations.
Despite the incorrectness of optimal control problems with a quadratic functional, the gradient projection method did not show a tendency to «dispersion» and gave a convergent sequence of controls.