bluuebunny/crossref_metadata_2025 huggingface dataset:
Od conjoint analysis do metod wyborów opartych na menu
Authors: Rybicka Aneta
Published: September 2024

One of most popular methods applied in stated preference evaluation is conjoint analysis. While doing preference evaluations with the application of conjoint analysis, a respondent is presented a set of profiles (products or services) to evaluate. Respondents are asked to rank or order profiles. While using discrete choice studies we don't ask respondents to rank or order profiles, but we present a set of profiles and ask him or her to choose either one or none of them. Preference measurement and evaluation with the application of adaptive conjoint analysis is done in two phases. The respondent evaluates preferences towards levels of all attributes, then evaluates selected pairs and chooses one profile. This method allows for the use of a large number of attributes and levels. But because of the need to choose between pairs of profiles it is different from the consumer behaviour market. To get more real-life data, an adaptive discrete choice method was proposed to describe both compensatory and non-compensatory behaviours. Menu-based choice, designed for markets where a consumer can make choices from the menu, is the newest method of preference analysis. The main aim of the paper is to describe all of the methods, starting from conjoint analysis on through to menu-based choice.
Orientacja hybrydowa a nowe podejścia w marketingu
Authors: Chlipała Paweł
Published: September 2024

The paper presents the possibility of using the hybrid orientation called "the third methodological movement" in the study of modern marketing concepts, such as value-based marketing, relationship marketing, social marketing or international marketing. This article presents the methodological basis of an integrated approach, presenting its concept, nature and typologies. It then presents the opportunities and limitations of using an integrated, hybrid approach to research marketing concepts.
Wielowymiarowa analiza społeczno-demograficznych aspektów wykorzystania Internetu
Authors: Grześkowiak Alicja , Stanimir Agnieszka
Published: September 2024

The objective of this paper was to test a hypothesis on the diversity in the use of computers for online communication, shopping activities, entertainment and information acquisition. The differences between people belonging to two age groups - those who started and ended their professional careers either in 2003 or 2011 - were analysed. The study included the additional socio-demographic characteristics: gender, level of education and place of residence. The data were retrieved from the "Social Diagnosis", and logistic regression and correspondence analysis were used. The research findings confirm the differences in Internet use by the groups of younger and older people, taking into account other variables.
Funkcjonalna analiza głównych składowych w badaniu zmian liczby studentów w czasie w krajach europejskich
Authors: Sej-Kolasa Małgorzata , Sztemberg-Lewandowska Mirosława
Published: September 2024

Principal component analysis (PCA) transforms an original set of variables into a new orthogonal set called principal components. Functional principal component analysis (FPCA) has the same advantages as classical principal component analysis while also enabling the analysis of dynamic data. The main difference between them is that PCA is based on multidimensional data and FPCA is based on functional data. The functional data are curves, surfaces or anything else varying over a continuum. They are not a single observation. The main aim of the paper is to show the usefulness of applying functional principal component analysis in order to analyse longitudinal data. The paper presents an example of how this method has been used based on the analysis of changes in the number of students (over time) in chosen European countries. Visualisation of the results makes it possible to compare countries and detect outliers.
Metoda k-średnich w segmentacji emerytów na podstawie priorytetów życiowych
Authors: Olejnik Iwona , Skikiewicz Robert
Published: September 2024

The article compares the results of the segmentation of retirees done using the k-means method on the basis of a set of behavioural variables and a combined set of behavioural, demographic and economic variables. On the basis of the behavioural set, segments of retirees which showed significant differences in the area of life priorities were obtained. Between these groups there were relatively small differences in their demographic and economic profile. In the case of the segmentation done on the basis of the combined set of variables, the results of segmentation were influenced to a greater extent by the demographic and economic variables. The segments of retirees became more easily identifiable, but the differences in the area of behavioural features decreased.
Rozwój regionalny - ujęcie systemowe
Authors: Kocurek Krzysztof
Published: September 2024

The starting point for the deliberations in this article is a definition of a region from the point of view of geographic, cultural, social, political and economic aspects, followed by a description of the concept of regional development. The article raises questions about the overall approach to the process of changes taking place in a given territory. It also explains the issue of regional policy reorientation. The aim of the article is to analyse the concept of regional development and the main challenges that lay before it.
Prawo do życia rodzinnego na tle ogólnie pojmowanej prywatności jednostki
Authors: Michałowska Kinga
Published: September 2024

The article examines the conceptual scope and the capacity of the right to privacy. The study analyses the conceptual scope of ways of formulating the right to privacy and its sources in the literature. In the light of this relationship: value - personal rights - right of the subject, the considerations center on proving the fundamental thesis of the article - that the right to family life is an independent value formulated within a framework of isolated personal rights. The considerations focus on the juxtaposition of the two rights - to privacy and to family life - to determine their mutual relationships and prove the thesis adopted at the beginning of the article.
Reglamentacja działalności gospodarczej w zakresie odbierania odpadów komunalnych od właścicieli nieruchomości oraz opróżniania zbiorników bezodpływowych
Authors: Piotrowska Aldona
Published: September 2024

Municipalities are required to organise the collection of municipal waste from pro­perty owners where residents live. Amendments to the Act of 13 September 1996 on maintaining cleanliness and order in municipalities, which entered into force on 1 January 2012, made changes to the business responsible for collecting and transporting waste from property owners and the emptying of septic tanks and transportation of liquid waste. The amendment of the law replaced the requirement to register regulated activity only for businesses engaged in activities related to the collection of waste but left alone the required licensing of companies engaged in emptying septic tanks and transporting liquid waste. This decision is questionable from the point of view of the principle of proportionality in restricting the freedom of economic activity.
Odmowa podjęcia uchwały przez Sąd Najwyższy i jej prawne uwarunkowanie
Authors: Wiatrowski Piotr
Published: September 2024

Supreme Court resolutions taken in response to concrete and abstract legal questions are the primary instrument for ensuring the uniform application of case law in court decisions. The article examines legal conditions and the grounds by which the Supreme Court might reject a resolution in response to a legal question brought before it. It also presents specific cases of such judgments based on Supreme Court jurisdiction.
Wskaźnikowa i punktowa analiza funkcjonalności systemów zarządzania procesowego
Authors: Stabryła Adam
Published: September 2024

The paper presents the concept of functionality analysis as a universal research method applied in organisational and technical as well as economic and social systems. The methodology of functionality analysis is based on a functional approach, which indicates that systems are analysed from the perspective of the functions they perform. A functional approach translates to various methodologies, constituting a link between diagnosing research and designing. The paper presents functionality analysis as a diagnostic method focused on ratio and point assessment.
Projektowanie strategii zarządzania
Authors: Sołtysik Mariusz
Published: September 2024

Recent studies on the search for a formula design business strategy have focused on development and restructuring. The universalist approach, marketing and financials are predominant in these studies. They focus on ways to achieve competitive advantage, sustainable development, and concern also the choice of sectors and market segments, sources of financing, and the allocation of funds. The purpose of this article is to review approaches to design and to provide a universal interpretation of management strategies. More specifically, it seeks to review design process management strategy, including the design of global business and organisational change.
Wybrane koncepcje klasyfikacji metod zarządzania jakością
Authors: Wawak Sławomir
Published: September 2024

A catalogue of methods will help scientists studying management and decision-makers in business alike as it allows them to select and use appropriate tools. In the literature, there is no shortage of classification of quality management methods. However, they are mostly incomplete or ambiguous. This paper presents an overview of approaches to the classification of management methods and proposes two suggestions for classifying quality management methods.
Główne elementy metodyki oceny współpracy w outsourcingu personalnym
Authors: Małkus Tomasz
Published: September 2024

The expectations of organisations implementating HR outsourcing can differ significantly. Assumptions about the expected results of cooperation with a service provider substantially affect the assessment of the cooperation scheme. Depending on the importance of HR outsourcing in the strategy, assessment may be focused on the results achieved immediately after cooperation, but also in a longer strategic perspective. The purpose of this article is to present a methodology for evaluating cooperation in HR outsourcing. It considers the characteristics of the research area (cooperation with a specialised service provider), a course of conduct, examples of criteria and characteristics of selected tools that can be used in this field, including recommendations for their implementation.
Analiza preferencji interesariuszy negocjacji w zarządzaniu projektami
Authors: Kozina Andrzej
Published: September 2024

The objective of the paper is to present methodological principles used in analysing stakeholder preferences in the context of negotiations planning and to discuss the practical application of those principles in a particular project. The analysis of stakeholder negotiations in project management is first discussed. This is followed by a discussion of general methodological rules of such analysis along with a specific model for analysing stakeholder preferences, based on multi-criteria decision making theory. An empirical presentation of stakeholder preference analysis for an IT project concludes the paper.
Wpływ fluktuacji na rynku private equity i venture capital na innowacyjność w wybranych krajach Europy Środkowo-Wschodniej
Authors: Banaś Grzegorz , Bill Rafał
Published: September 2024

The article looks at the level of innovation as measured by the Global Innovation Index and the level of investment through venture capital (VC) and private equity (PE) in Poland, Romania, Bulgaria, Hungary and Czech Republic. To measure the performance of innovation, data was taken from Global Innovation Index reports published by INSEAD; VC and PE were estimated using the accounts of European Private Equity and Venture Capital Association. The research verifies the argument that PE and VC investments have an impact on state innovation if the level of those investments is above the average of other contributors. We tested the correlation for the years 2009-2011, which are considered the peak of the economic crisis.
Analiza struktury portfela inwestycyjnego otwartych funduszy emerytalnych
Authors: Bolisęga Maciej
Published: September 2024

The system of open pension funds (OFE) is a consequence of the pension re-organisation that took place in 1999 in Poland. Since then, thanks to the size of assets under management, OFEs have become one of the most important players on the Polish financial market. The aim of this analysis is to examine aggregated portfolio structure in terms of both debt instruments and shares. The study also comprises a description of legal restrictions regarding investment policy. Two approaches have been implemented for the shares of an aggregated portfolio. One involves an analysis focused on stocks in which OFEs invested the highest absolute amount. The other approach focused on stocks in which OFEs had obtained the highest shareholder stake. Our results suggest that, in terms of relative stake of shareholders, OFEs invest the most in medium-size companies. However, further studies must take into account more factors in order to provide a more comprehensive view of the issue.
Problem ukrytego długu publicznego w Polsce
Authors: Kasperowicz-Stępień Alicja
Published: September 2024

The largest problem facing Polish public finance today is the rapid growth in public debt and the attendant costs of servicing it. According to government calculations, in 2010 public debt reached 54.9% of GDP. Yet to the government calculations must be added hidden public debt, which actually measures 180% of GDP. This paper analyses the level of evident and hidden public debt in Poland.
Infrastruktura ICT polskich przedsiębiorstw w układzie regionalnym
Authors: Kiercz Oskar
Published: September 2024

The growing disparity in development between Poland's regions has become a pressing problem for the country's economy today. Here disparity applies not only to the standard of living, but also to information and communication technologies (ICTs) used by both individual and larger business entities, and it indicates the division into well-developed and underdeveloped regions. This phenomenon is slowing down the country's socio-economic development. The article assesses the use of ICTs by Polish enterprises in 2010 relative to other EU member countries and regional structures based on statistical data provided by Eurostat and The Central Office of Statistics.
Metody badawcze w obszarze polemologii
Authors: Krupa Marcin
Published: September 2024

The research focuses on a phenomenon with a political, cultural and sociological nature - war. One purpose of my research is to link this phenomenon with the economy. The wider purpose is to raise political science and sociology to a higher level of analysis with the aim of reducing and unifying the social sciences to a stricter level of analysis. This research objective uses the example of war, and enlists mathematical instruments associated not only with the business cycle. Tests are performed on the example of the U.S. business cycle and that country's military activity. The research shows the reciprocal relationship of these events, the state of the U.S. economy, determined by variations in the parameters of the national income and related to a growing propensity for military activity, which in turn, as the research shows, reduces the number of wars on a global scale. Other aspects of the paper include a description of the history of the research process, the phenomenon of war and issues and problems from the philosophy of science.
Finansowanie zadań publicznych na przykładzie elektroenergetycznej działalności przesyłowej
Authors: Grzegorczyk Filip
Published: September 2024

The paper analyses the financial aspects of the electric Transmission System Operator (TSO-E), ultimately proving that TSO-E performs exclusively public works. Research conducted for the essay shows the disadvantages of the financing methodology and financial duties imposed on TSO-E. These disadvantages are not crucial only now, at a time when TSO-E is not making the necessary investments due to legal barriers and the investment process. However, it must be emphasised that removing the barriers will certainly show that the TSO-E financing system is illogical, the financial duties imposed on TSO-E are too far-reaching and, last but not least, the organisational form of the TSO-E is flawed. These are also the reasons that de lege ferenda proposals have been formulated to improve the current situation.
Prosodic Effects of Focus and Constituency in Mandarin and in English
Authors: Zhang Wei , Clayards Meghan , Wagner Michael
Published: September 2024

The prosody of an utterance encodes multiple types of information simultaneously, including information status of constituents—for example, by modulations in prosodic prominence to encode focus—and information about syntactic constituent structure—by modulations of prosodic phrasing. According to many prosodic theories, however, focus and constituent structure interact with each in their effects on prominence and phrasing respectively. Focus early in an utterance is sometimes assumed to preempt the realization of tonal events later in the utterance, thus neutralizing syntactically-motivated phrasing distinctions. Other accounts assume that focus and constituent structure exert their effects on prominence and phrasing in an additive way. The current study compares English and Mandarin and investigates to what extent the correlates of focus and constituency interact with each other in shaping the prosody in production. The results show that syntax-induced phrasing distinctions are still encoded post-focally in both languages, providing new evidence for the view that different functions can be encoded orthogonally in prosody. Additionally, we found that while the two languages realize phrasing in roughly same way, they differ in their acoustic realization of focus. Mandarin relies more on F0 modulation than English, and Mandarin lexical tones interact with focus realization.
"We Don't Need Any More Martyrs": Anti-War Protests at the University of Iowa 1970
Authors: Kapsner Jack
Published: September 2024

This thesis argues that the May 1970 anti-Vietnam War protests at the University of Iowa were nonviolent compared to similar demonstrations at other colleges. This was due to the actions of University President Willard “Sandy” Boyd, who was able to strike a delicate balance between maintaining civil order and protecting the right to protest. Students protested the joint U.S.-South Vietnamese invasion of Cambodia and the killings of students at Kent State University during a time of intense political upheaval. American politicians and citizens debated how to handle the war in Vietnam best and what course of action to take when coping with anti-war demonstrations. This thesis examines the protests at the University of Iowa to understand better the local political dynamics and how local leaders coped with a dynamic political environment. This thesis uses sources from the University of Iowa archives, the Iowa State Historical Society, and the Daily Iowan archives. While many college and government officials chose to adopt repressive stances towards the protests that occurred nationally, the Iowa protests were de-escalated without any deaths. This resolution gives current elected officials a model of how to maintain civil order without violating the rights of American citizens.
Information properties of frequency characteristics of dynamic cutting systems in the diagnosis of tool wear
Authors:   Don State Technical University, Rostov-on-Don, Russian Federation, Zakovorotny Vilor , Gvindjiliya Valery ,   Don State Technical University, Rostov-on-Don, Russian Federation, Kislov Kirill ,   Don State Technical University, Rostov-on-Don, Russian Federation
Published: September 2024

Introduction. One of the directions for increasing the efficiency of cutting is related to the creation of tool wear diagnostic systems. Algorithms and devices have been developed that evaluate wear based on analysis of the vibroacoustic emission signal. These algorithms, as a rule, do not reveal the nature of its formation and the reasons for the change as wear develops. Subject. The paper is devoted to the analysis of the reasons for changes in vibration properties with the development of tool wear. The aim of the work is to study the changes in the frequency characteristics of a dynamic cutting system caused by the development of wear, and to build diagnostic information models on this basis, as well as its use in industry. Method and methodology. The results of mathematical simulation of a perturbed dynamic cutting system are presented, in which the observed vibration sequences are a consequence of disturbances transformed by a dynamic system, the parameters of which depend on wear. Two frequency ranges are considered. Results and discussions. The first range includes frequencies that lie within the bandwidth of the instrument subsystem. The second is outside of it. In the first frequency range, it has been analytically and experimentally proven that the development of wear leads to fundamental changes in the frequency properties of the cutting system as a converter of disturbances into tool vibrations. There is a shift in the natural frequencies of the oscillatory circuits formed by the cutting system, a decrease in its quality factor, and as wear develops, some identified features of the vibration spectra appear, including the ratio of the low-frequency and high-frequency parts of the spectrum, etc. In the second frequency range, a model of force emission in the form of a random pulse sequence is considered and wear is displayed in it. The results of studying the coherence function between the forces acting on the tool and vibrational displacement are presented. Information models of wear are proposed, an example of an information model of wear and the results of its use in industry are given.
Features of the use of tool electrodes manufactured by additive technologies in electrical discharge machining of products
Authors:   Perm National Research Polytechnic University, Russian Federation, Ablyaz Timur , Blokhin Vladimir ,   Perm National Research Polytechnic University, Russian Federation, Shlykov Evgeniy ,   Perm National Research Polytechnic University, Russian Federation, Muratov Karim ,   Perm National Research Polytechnic University, Russian Federation, Osinnikov Ilya ,   Perm National Research Polytechnic University, Russian Federation
Published: September 2024

Introduction. The paper presents the results of a study of the use of a tool electrode (TE), manufactured by selective laser alloying from MS1 maraging steel powder for copy-piercing electrical discharge machining (EDM). Purpose of the work: experimental study of the features of the use of additively manufactured TE in the EDM of critical products. Research methods. The specimens were prepared using a ReaLizer SLM 50 system. The starting material was spherical MS1 powder with an average particle size of 30 μm. To test the modes and select a TE sample with the least number of surface defects, four manufacturing modes were tested, and the best TE sample was selected for further research. The EDM was carried out on EMT Smart CNC equipment in a dielectric oil environment. The specimens were installed in a clamp with straight polarity and were used as TE; a 0.12C-18Сr-10Ni-Тi steel plate served as the workpiece electrode. The study was conducted using a factorial experiment (type 23) with a central design. The input data of the factorial experiment is the current I (A), voltage U (W), pulse on time Ton (μs). The output parameters were the roughness parameter Ra and tool electrode wear γ. The roughness parameter Ra was measured using a Mahr Perthometer S2. Results and discussion. TE samples were made from MS1 powder using the SLS method; the highest quality TE sample No. 4 was selected for EDM. Empirical equations are obtained that describe the relationship between the roughness parameter Ra and tool electrode wear γ, depending on the EDM modes. At the minimum mode with a current I = 4 A and a voltage U = 50 V, the tool electrode wear is γ = 0.0063875 g. The maximum tool electrode wear is γ = 0.13938 g with a current I = 8 A and a voltage U = 50 V. It is established that at a constant pulse on time Ton = 75 μs, the smallest roughness Ra = 2.83 μm is obtained at a current of I = 4 A and a voltage U = 100 V, and the maximum roughness is Ra = 4.1568 μm at I = 8 A and U = 100 V.
Patterns of reverse-polarity plasma torches wear during cutting of thick rolled sheets
Authors:   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Sidorov Evgeny , Grinenko Artem ,   ITS-Siberia LLC, Krasnoyarsk, Russian Federation, Chumaevsky Andrey ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Panfilov Alexander ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Knyazhev Evgeny ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Nikolaeva Alexandra ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Cheremnov Andrey ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Rubtsov Valery ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Utyaganova Veronika ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Osipovich Ksenia ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Kolubaev Evgeniy ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation
Published: September 2024

The introduction describes the features of the process of plasma cutting of various metals and alloys using reverse-polarity plasma torches with and the features of cutting thick sheets. The purpose of the work is to study the wear process of plasma torches operating on reverse polarity current when cutting thick rolled sheets of aluminum and titanium alloys. Research methods include optical and scanning electron microscopy, filming of the cutting process and visual inspection of plasma torch elements after receiving specimens. Results and discussion. The section shows the appearance of the main working elements of the plasma torch after cutting in various modes, which led to both stable and gradual wear and to catastrophic failure of the plasma torch. The results of structural studies of the main characteristic zones of nozzles and electrodes after cutting are presented. The studies carried out made it possible to establish the main reasons for the failure of the working elements reverse-polarity plasma torches. The causes of catastrophic failure of plasma torches include failure to maintain the gap between the nozzle and the electrode and melting of the channel of gas supply into the discharge chamber. The wear of nozzles and electrodes in a stable mode can be intensified due to abnormal operation of the starting arc, the presence of manufacturing inaccuracies and excess gas pressure. In conclusion, the main conclusions based on the results of the research are formulated. The process of wear of electrodes, nozzles and body elements of plasma torches during operation at high electric arc power values is described.
Corrosion properties of CuAl9Mn2/ER 321 composites formed by dual-wire-feed electron beam additive manufacturing
Authors:   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Semin Viktor , Panfilov Aleksander ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Utyaganova Veronika ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Vorontsov Andrey ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Zykova Anna ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation
Published: September 2024

Introduction. The development of novel materials based on copper alloys and stainless steel, as well as the determination of the optimal parameters for its processing make it possible to expand the area of its implementation, increase efficiency and service life of tools and constructions. The load-bearing parts of marine equipment (bearing constructions, piston cylinders, pumps, valves, gears, rotary instruments, etc.), made of austenitic steels or aluminum bronze, are in direct contact with sea water, so the problem of increasing its corrosion resistance in the presence of strong oxidizing agents (Cl-, F- anions) is relevant. One of the advanced and actively researched methods for producing copper/steel composites is additive manufacturing that allow fabricating complex parts through layer-by-layer growth. In particular, the synthesis of composites based on aluminum bronze and steel can be realized by wire-feed electron beam additive manufacturing. In order to implement composite materials produced via additive technologies in a humid (marine) climate, it is necessary to ensure not only high strength, but also corrosion properties. The purpose of this work is to study the corrosion resistance of composites, based on aluminum bronze CuAl9Mn2 and stainless steel ER 321 produced by dual-wire-feed electron beam additive manufacturing. Research methods. Examination of the surface of CuAl9Mn2/ER 321 composites before and after corrosion tests was carried out by methods of voltammetry and electrochemical impedance spectroscopy using a potentiostat-galvanostat. Results and discussion. Using a complex of electrochemical methods, it is revealed that the developed composites with a volume fraction of steel ≥ 25% demonstrate a significant decrease in anodic current densities and a simultaneous increase in charge transfer resistance. Composites with a steel content of 75 vol. % are characterized by the highest corrosion properties in 3.5 wt. % NaCl solution, which is referred to a reduction in corrosion rate by 9.5 times compared to aluminum bronze. It is shown that the main processes occurring on the surface of the composites (CuAl9Mn2 + ER 321) are anodic oxidation of copper and iron, leading to the formation of corrosion products – Cu2O and FeCl2.
Investigation of hardness behavior in aluminum matrix composites reinforced with coconut shell ash and red mud using Taguchi analysis
Authors:   Amity University Rajasthan, Jaipur, India, Dewangan Rishi , Sharma Bhupendra ,   Amity University Uttar Pradesh, Noida, India, Sharma Shyam ,   Manipal University, Jaipur, India
Published: September 2024

Introduction: in present scenario, light and high strength aluminium metal matrix composite are extensively used due to its high mechanical and tribological properties. Aluminium metal matrix composite reinforced with ceramic and industrial waste can customize its mechanical-chemical behavior. The purpose of the work: to create an aluminum matrix composite material using ceramic (primary) and industrial (secondary) waste represented by red mud and coconut shell ash, respectively. The mass fraction of the strengthening phase varied from 5 to 12.5 wt. % respectively with the residual mass percentage of the aluminum alloy. Method of investigation: nine specimens of composite materials were prepared by stir casting. Stirring was carried out at a speed of 50 to 100 rpm for 20 minutes at a temperature of 800 °C. Result and Discussion: the hardness behavior of the aluminum metal matrix composite was studied at an indentation load of 10, 15 and 20 kN. Taguchi method with L27 orthogonal array was selected to conduct analysis of variance (ANOVA) and regression analysis by selecting the mass percentage of red mud and mass percentage of coconut shell ash. The indentation load was used as an input parameter, and the hardness behavior was taken as an output parameter. The signal-to-noise ratio, response rank table, contour plot, and normal probability plot are investigated and it is found that hardness values improve with the addition of both reinforcing components and indenter load. The results show that the hardness value varies from 33.34 HB to 53.44 HB, and the effect of red mud mass percentage is more significant than the indenter load and coconut shell ash mass percentage.
The effect of technological parameters on the microstructure and properties of the AlSiMg alloy obtained by selective laser melting
Authors:   National Research Tomsk Polytechnic University, Russian Federation, Saprykina Natalia , Saprykin Alexandr ,   National Research Tomsk Polytechnic University, Russian Federation, Sharkeev Yurii ,   Institute of Strength Physics and Materials Sciences SB RAS, Tomsk, Russian Federation, Ibragimov Egor ,   National Research Tomsk Polytechnic University, Russian Federation
Published: September 2024

Introduction. The development of additive technologies is aimed at the synthesis of new powder compositions for selective laser melting plants, the study of the effect of mode parameters on the stable quality of products. The purpose of this work is to study the effect of the scanning strategy on the microstructure, elemental composition, porosity and density of specimens obtained by selective laser melting from non-spherical powders (Al — 91 wt. %, Si — 8 wt. %, Mg — 1 wt. %), subjected to special preparation to determine the optimal conditions for selective laser melting. The research methods are methods of X-ray diffraction and X-ray phase analysis, transmission electron microscopy. The paper examines specimens formed using four different scanning strategies. Results and discussions. A promising aluminum alloy AlSi8Mg is developed for selective laser melting. The material has good manufacturability and low powder cost. The technological parameters of melting make it possible to form a thin structure with a low level of porosity. The mechanism of influence of the scanning strategy on porosity, surface morphology, relative density and microstructure is investigated. A specimen from the AlSi8Mg powder composition with a high relative density of 99.97 % is produced by selective laser melting with an energy density of 200 J/mm3, a specimen scanning circuit when the direction of laser movement changes by an angle of 90° each odd layer. It is proved that the density of the AlSiMg alloy depends on the scanning strategy used. The calculated density of the specimen was 2.5 g/cm3, which corresponds to the density of silumin. Analysis of SEM images and maps of the distribution of elements (Al, Mg, Si) of the specimens showed that different specimen formation strategies do not affect the nature of silicon distribution. A unique grain structure is observed in the resulting AlSi8Mg alloy. The melt pool consists of small grains along the border and large grains in the center. The formation of fine grains is explained by the addition of Si and the high cooling rate during selective laser melting.
Wear resistance and corrosion behavior of Cu-Ti coatings in SBF solution
Authors:   Khabarovsk Federal Research Center FEB RAS, Russian Federation, Burkov Alexander , Dvornik Maxim ,   Khabarovsk Federal Research Center FEB RAS, Russian Federation, Kulik Maria ,   Khabarovsk Federal Research Center FEB RAS, Russian Federation, Bytsura Alexandra ,   Khabarovsk Federal Research Center FEB RAS, Russian Federation
Published: September 2024

Introduction. Currently, titanium and its alloys have become the most popular metal implantable biomaterials. However, the main disadvantage of titanium alloys is low wear resistance due to high viscosity. It is known that copper-titanium coatings effectively improve the antibacterial properties of titanium alloy and at the same time increase its wear resistance. Purpose of the work is to study the effects of a solution simulating body fluid on corrosion properties, friction coefficient and the wear of copper-titanium coatings obtained by electrospark deposition method of the Ti-6Al-4V alloy. Method. A non-localized electrode consisting of copper and titanium granules in various ratios was used to form copper-titanium coatings on a titanium alloy by electrospark deposition. The structure of the coatings was examined using a DRON-7 X-ray diffractometer in Cu-Kα radiation and an X-max 80 energy dispersive spectrometer. The antibacterial activity of the deposited Cu-Ti coatings was studied on a non-pathogenic gram-negative culture of Escherichia coli. Polarization tests in SBF solution were carried out using a P-40X potentiostat with an impedance measurement module. The metal content in the SBF solution after immersion of the samples was measured using an ICP-MS 2000 mass spectrometer. The tribological characteristics of the coatings according to the ASTM G99-17 standard using the “ball-on-disk” scheme with sliding friction in the SBF solution at loads of 10 and 25 N were examined. Results and discussions. It is shown that the bactericidal activity of Cu-Ti coated samples to a non-pathogenic culture of Escherichia coli increased monotonously with an increase in copper content. With copper concentration increasing, the corrosion current density of the coatings increased from 3.455 to 17.570 μA/cm2. It is shown that the SBF solution accelerates the wear of a titanium alloy many times over due to its interaction with the electrolyte via the oxidative wear mechanism. The use of Cu-Ti coatings allows reducing the friction coefficient and greatly decreasing the wear of Ti-6Al-4V alloy in the presence of an electrolyte.
Thermomechanical rolling in well casing production (research review)
Authors:   JSC ", Baraboshkin Kirill ,   Severstal Management",   ,  Cherepovets, Russian Federation, Adigamov Ruslan ,   JSC "Severstal Management",  Cherepovets, Russian Federation, Yusupov Vladimir ,   Baikov Institute of Metallurgy and Materials Science, RAS  Moscow, Kozhevnikova Irina ,   Cherepovets State University, Russian Federation, Karlina Antonina ,   JSC "Severstal Management",  Cherepovets, Russian Federation
Published: September 2024

Introduction. The modern oil and gas industry requires the development of high strength materials for well casing. Changes in rolled steel production technologies are one of the urgent tasks. Reducing the cost of high quality steel well casing is becoming a major challenge for the oil and gas industry. Multiphase microstructures containing acicular ferrite or an acicular ferrite-dominated phase exhibit good complex properties in HSLA steels. This paper focuses on the results obtained using modern methods of thermomechanical rolling. Results and discussion. This work analyzes the characteristics of thermomechanical rolling technologies and its impact on the microstructure of rolled steel for well casing. It is shown that predicting mechanical properties based on the microstructural characteristics of steel is complicated due to the large number of parameters involved. This requires an optimal microstructure of the steel. A satisfactory microstructure depends on several factors, such as chemical composition, hot work processing, and accelerated cooling. Alloying elements have a complex effect on the properties of steel, and alloying additives are usually introduced into the steel composition. From a metallurgical point of view, the choice of alloying elements and the metallurgical process can greatly influence the resulting microstructure. Conclusion. This review reports the most representative study regarding thermomechanical rolling technologies and microstructural factors in well casing steels. It includes a summary of the most important process variables, material properties, regulatory guidelines, and microstructural and mechanical properties of the metal for well casing production. This review is intended to benefit readers from a variety of backgrounds, from non-metal forming or materials scientists to various industrial application specialists and researchers.
Characterizing the mechanical behavior of eco-friendly hybrid polymer composites with jute and Sida cordifolia fibers
Authors:   Amity University Uttar Pradesh, Noida, India, Sharma Bhupendra , Dewangan Rishi ,   Amity University Rajasthan, Jaipur, India, Sharma Shyam ,   Manipal University, Jaipur, India
Published: September 2024

Introduction. Recognition of the medicinal properties of plants is an integral part of traditional Indian health systems such as Unani, Siddha, Naturopathy and Ayurveda. Among others, Sida cordifolia, a member of the Malvaceae family, is especially celebrated in Ayurvedic medicine for its outstanding chemical properties. This plant grows in the subtropical and tropical climate of India and symbolizes the global shift towards more environmentally friendly materials. Given the rising environmental concerns, there is an increased demand for biodegradable and renewable resources for industrial applications, especially for reinforcing polymer matrices with natural fibers. The purpose of this study is to investigate the effectiveness of Sida cordifolia fibers combined with jute for reinforcing polylactic acid (PLA) composites. This highlights its potential to improve both environmental quality and mechanical properties of materials. Materials and method. The study involved the fabrication of four different composite specimens: : a solely 4-layered jute fiber mat, untreated Sida cordifolia fibers combined with a 4-layered jute mat, and Sida cordifolia fibers treated with benzoylation combined with a 4-layered jute mat. These composites were subjected to mechanical testing focusing on tensile strength and flexural strength. Its microstructural analysis was also carried out. Results and discussion. The results show that benzoylation-treated Sida cordifolia fibers exhibit significantly higher strength compared to its untreated counterparts. At the same time, an increase in the proportion of Sida cordifolia fibers in composites while maintaining a constant total mass correlates with an increase in the strength of the materials. These results indicate that Sida cordifolia and jute fiber-reinforced PLA composites can provide a competitive, environmentally friendly alternative to synthetic fiber-reinforced composites in a variety of industrial applications. In conclusion, treated natural fibers like Sida cordifolia can significantly improve the mechanical properties of polymer composites, supporting its use as environmentally friendly, high-performance materials in a variety of industries. This research not only promotes the use of natural fibers for commercial applications, but also contributes to the larger goal of sustainable materials science.
Fine structure features of Ni-Al coatings obtained by high velocity atmospheric plasma spraying
Authors:   Novosibirsk State Technical University, Russian Federation, Kornienko Elena , Gulyaev Igor ,   Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russian Federation, Smirnov Alexandr ,   Novosibirsk State Technical University, Russian Federation, Plotnikova Natalya ,   Novosibirsk State Technical University, Russian Federation, Kuzmin Viktor ,   Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russian Federation, Golovakhin Valeriy ,   Novosibirsk State Technical University, Russian Federation, Tambovtsev Alexandr ,   Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russian Federation, Tyryshkin Pavel ,   Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russian Federation, Sergachev Dmitry ,   Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russian Federation
Published: September 2024

Introduction. Development of Ni-Al intermetallic compounds is one of the priority directions of modern machine building. Due to such characteristics as high heat resistance, high temperature strength, and low density, nickel aluminides are used as functional coatings in the aerospace industry. The main methods of Ni-Al coating surfacing are High-Velocity Oxygen-Fuel and High-Velocity Air-Fuel spraying (HVOF and HVAF), atmospheric plasma spraying (APS) and its modification such as High-Velocity Atmospheric Plasma spraying (HV-APS) which provides non-equilibrium cooling conditions. Since there are eight different intermetallic compounds, as well as martensite transformation, Ni-Al coatings is quite interesting to study. The work purpose is to study the features of the martensitic structure in HV-APS coatings, and also to establish the effect of heating temperature on its decomposition. Materials and methods. Ni-Al coatings were surfaced onto a low-carbon steel substrate using the HV-APS method. Studies of the fine structure of the coatings were carried out using transmission electron microscopy (TEM). In addition, the influence heating temperature on structural transformations of the coatings was analyzed. Results and discussion. Two types of particles are formed in HV-APS coatings: with a dendritic and granular structure. The most part of HV-APS coatings consists of particles with a two-phase grain structure (NiхAl1-х and γ'-Ni3Al grains). Only NiхAl1-x grains undergo martensitic transformation at cooling. Martensite in large grains (sizes greater than 500 nm) has a lamellar structure, while small grains are completely transformed into one martensite plate. In addition, the coatings contain grains in which martensite plates (NiхAl1-х) and β-phases alternated. It is shown the behavior of martensitic plates at colliding with each other, as well as with the γ′-Ni3Al grain. Heating up to 400 °C contribute the begins of martensite decomposition in individual grains with the release of a secondary phase; after heating up to 600 °C all martensite dissolves.