Materials Science Research Articles

Heat and mass transfer analysis in flow of Walter's B nanofluid: A numerical study of dual solutions

AbstractThis study investigates the behavior of Walter's liquid B fluid over a biaxially stretching/shrinking surface for Homann stagnation point flow, focusing on the rheological properties that are crucial for understanding physical phenomena in engineering and industrial processes. The problem is modeled using Buongiorno's model in the presence of a permeable surface subject to heat generation/absorption, Ohmic heating, and chemical reactions influenced by Arrhenius activation energy. The governing partial differential equations are solved numerically using an appropriate similarity transformation, and the results are graphically analyzed via MATLAB's bvp5c solver. The study highlights the importance of characterizing the intricate properties of viscoelastic fluids, with potential applications in biomedical engineering and materials science. The findings reveal the coexistence of two distinct flow regimes and dual solutions are obtained. It is noted that the activation energy parameter is shown to enhance mass distribution in both solutions, while chemical reactions accelerate reactant conversion but reduce mass distribution. Additionally, an increase in viscoelasticity shifts the fluid's behavior towards elasticity, creating greater resistance to shear deformation and reducing both velocity profiles.

Versatile Mechanochemical Reactions via Tailored Force Transmission in Mechanophores

In polymer mechanochemistry, regulating the intrinsic mechanical reactivity of a mechanophore offers extensive opportunities in material science, enabling the development of hierarchical and multifunctional polymer‐based materials. Recent advances have focused on innovating various types of mechanophores with inherent reactivity (e.g. regioselectivity and stereoselectivity). However, little attention has been given to modulating their reactivity by tailoring force transmission within mechanophores. Here, we introduce a novel approach through the implementation of a cyclic pulling geometry into an anthracene‐maleimide (AM) mechanophore. This approach manipulates force transmission within the mechanophore and effectively regulates its reactivity from 0.0160 min‐1 to 0.00133 min‐1, achieving up to a 12‐fold change. Mechanochemical coupling analysis suggests that the split force transmission within the ring may suppress the sequential bond rupture mechanism in AM mechanophores under applied forces. By leveraging the distinct force transmission pathways within cyclic and linear AM mechanophores, we covalently integrate them with a spiropyran mechanophore to design tandem mechanophore systems for hierarchical mechanochemical activation. These findings highlight the efficacy and versatility of the cyclic pulling strategy in modulating mechanophore reactivity, providing valuable insights for the design of tunable multifunctional polymer‐based materials.

Ortho Arylation of N-Aryl Amides and the Construction of Diagonal Tetraarylbenzenediamines and N-Doped Fulminenes via BBr3-Derived Dibromoboracycles.

The synthesis of biaryl amides, which are prevalent motifs in bioactive molecules, often necessitates lengthy and inefficient procedures. To address these limitations, catalytic C-H activation protocols have emerged, enabling the direct ortho-arylation of aryl amides. However, these protocols often suffer from issues such as lack of selectivity, reliance on stoichiometric oxidants, and the requirement for excess reagents and harsh reaction conditions. To overcome these challenges, we present a novel and highly selective protocol for the ortho-arylation of N-aryl amides and ureas. The high selectivity originates from the directed installation of BBr3 to form a boracycle, which then undergoes cross-coupling with an aryl halide. Our method offers significant advantages, including mild reaction conditions, excellent site-specificity, and scalability. The protocol demonstrates broad compatibility with a diverse range of readily accessible functionalized anilides and aryl iodides, as evidenced by 55 successful examples yielding products in the 30-95% range. Furthermore, our methodology surpasses conventional approaches by facilitating the one-pot selective diagonal diarylation of dianilides. This capability unlocks the construction of previously unattainable diagonal aryl systems, which serve as valuable precursors for the synthesis of diagonal tetraarylbenzenediamines and N-doped fulminene, two crucial compound classes in materials science.

Increasing the Wear Resistance of the Impellers of Electrical Centrifugal Submersible Pumps Through Repair

Objective: This research investigates the challenges of maintaining electrical submersible pumps (ESP) and develop effective repair techniques to enhance their reliability and efficiency. Theoretical Framework: The research draws upon theories and models related to pump maintenance, materials science, and corrosion prevention. Methodology: A case study approach was adopted, focusing on a Weir VTP submersible pump in continuous operation for 15 years. The pump's condition was assessed, and the root causes of erosion and corrosion were identified. Laser cladding with a TiC coating was applied to the damaged areas. Results and Discussion: The results demonstrated a significant improvement in the pump's wear resistance and overall efficiency following the laser cladding treatment. The TiC coating effectively mitigated the effects of erosion and corrosion, extending the pump's lifespan and reducing maintenance costs. Research Implications: The findings of this research contribute to the development of more effective maintenance strategies for submersible centrifugal pumps. The use of laser cladding with TiC coatings can be applied to other types of pumps and machinery operating in harsh environments. This research also highlights the importance of regular inspections and preventive maintenance. Originality/Value: This study provides a practical solution to the problem of erosion and corrosion in submersible centrifugal pumps. The application of laser cladding with a TiC coating is a relatively novel approach, offering a more effective repair method compared to traditional techniques. The results can be applied to improve the reliability and efficiency of pumps in various industries.

THEORETICAL AND TECHNOLOGICAL KNOWLEDGE IN DISTANCE LEARNING: AN ANALYSIS OF TEACHING RESOURCES IN THE PEDAGOGY COURSE

This study analyzes the challenges and demands of students in the Pedagogy Distance Education Course at UFPR in relation to theoretical and technological knowledge. The research, of a qualitative and exploratory-descriptive nature, was conducted based on the netnographic methodology, examining the interaction of students with analog and digital teaching resources. Responses were collected from 41 students, through questionnaires applied in the Virtual Learning Environment (VLE). The results indicate that, although analog resources are still widely used and valued by students, digital technologies have become increasingly present and essential in the educational process. Among the main digital resources highlighted are the use of notebooks, cell phones, videoconferencing platforms, and digital materials. The study highlights the difficulties faced by students in managing these tools, especially in the context of the pandemic, which accelerated the transition to digital education. It is concluded that the integration between analog and digital resources is fundamental to meet the contemporary demands of Distance Education, requiring pedagogical planning that promotes inclusion and technological accessibility for all students, in order to enhance learning and promote effective teacher training.

Advances in flight control systems for modern commercial aircraft

Abstract. In consequence of the accelerated evolution of aviation technology, the flight control systems of commercial aircraft have undergone substantial technological advancement and system optimization. This paper presents a comprehensive analysis of the recent advancements and future trends in flight control systems for commercial aircraft. The fundamental concepts and historical evolution of flight control systems are delineated, with a particular emphasis on the evolution of autopilot systems and the technological advancements of flight control systems (FCS). Furthermore, it examines innovations in flight control algorithms, including adaptive control and intelligent algorithms, and investigates the impact of fault-tolerant design on flight safety. In terms of system integration, the integration of flight control systems with navigation and communication systems, as well as performance enhancements resulting from system optimization, is explored. In addition, it examines the potential impact of intelligence and networking on future flight control systems, with a particular focus on the prospects for the application of artificial intelligence, quantum computing, and new material technologies. The synthesis of these areas provides a systematic understanding of the technological evolution and future development of flight control systems for commercial aircraft.

Research on the Anchoring Performance of Green and Low-Carbon Anchoring Materials for Urban Rail Transit Foundation Pit Engineering

Abstract. Currently, most anchoring materials used in engineering are ordinary cement mortar, which has a slow hardening process, a prolonged early strength development, and high carbon emissions. In response to this, this paper proposes a new type of green anchoring material. The anchoring performance of this material is verified through indoor and field tests. Indoor tests on the basic properties of the green anchoring material were conducted, determining the optimal water-material ratio to be between 0.25 and 0.30 through tests on fluidity, setting time, and compressive strength. Field tests studied the ultimate bond strength of the new green anchoring material in typical soil-rock composite strata in Qingdao, confirming its rapid-setting and high-strength anchoring characteristics. The application of this anchoring material can reduce carbon emissions and realize the concept of green and low-carbon environmental protection.

Crystallization Control of Anionic Thiacalixarenes on Silicon Surface Coated with Cationic Poly(ethyleneimine).

Surface modification of solid substrates with organic molecules and polyelectrolytes is a promising strategy toward advanced soft materials due to the control of molecular arrangement and supramolecular organization; however, understanding the nature of interactions within the assembly is challenging. Here a facile approach to the control of the architecture of calixarene macrocycles on soft surfaces is presented through the interplay of weak interactions involving a solid silicon substrate, a cationic polyelectrolyte layer, and anionic sulfonatothiacalix[4]arene (STCA). Topological analysis of atomic force microscopy (AFM) images of STCA on silicon, as well as silicon wafers modified with neutral polyethylenimine (PEI) and cationic PEI-H+, indicates different surface morphology and assembly behavior of STCA on such substrates. Drop-casting a calixarene solution onto silicon induces the formation of chaotically oriented needle crystals. When there is globular PEI, a nucleation point for the STCA crystals is formed on the polyelectrolyte surface, which grows into rosette structures. In contrast, protonated PEI with a chain-like structure alters the self-organization of STCA on silicon surfaces, leading to a dense uniform fiber-like network. Density functional theory modeling of the system components' self-assembly reveals thermodynamically favorable face-to-face antiparallel aggregation of STCA monomers and contribution of H-bonding into PEI(PEI-H+)-STCA and Si-STCA association.

Cation‐Alginate Complexes and Their Hydrogels: A Powerful Toolkit for the Development of Next‐Generation Sustainable Functional Materials

AbstractThe use of materials from renewable sources instead of fossil fuels is a crucial step forward in the industrial transition toward sustainability. Among polysaccharides, alginate stands out as a versatile and eco‐friendly candidate due to its ability to form functional complexes with cations. This review provides an up‐to‐date and comprehensive description of alginate complexation with specific cations, focusing on how interaction forces can be harnessed to tailor the physicochemical properties of cation‐alginate‐based functional materials. Methodologies and approaches for the development and multiscale characterization of these materials are introduced and discussed. Alginate complexes with mono‐, di‐, tri‐, and tetravalent cations (namely Ag+, Mg2+, Ca2+, Sr2+, Ba2+, Mn2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Pb2+, UO22+, Cr3+, Fe3+, Al3+, Ga3+, Y3+, La3+, Ce3+, Nd3+, Eu3+, Tb3+, Gd3+, Zr4+, Th4+) are reviewed. Each cation is discussed individually, highlighting how it can uniquely influence the material properties thereby unlocking new potentials for the design of advanced functional materials. Key challenges and opportunities in applying these complexes across diverse fields, such as biomedicine, environmental remediation, food additives and supplements, flame retardants, sensors, supercapacitors, catalysis, and mechanical isolators are assessed, providing evidence of the transformative potential of cation‐alginate complexes for tackling global challenges and advancing cutting‐edge technologies.

PRE-REVOLUTIONARY HISTORIOGRAPHY OF THE PROBLEM OF PROOF OF MEMBERSHIP IN THE NOBILITY IN THE GRAND DUCHY OF LITHUANIA

The article examines the main pre-revolutionary works on the problem of proving one’s membership in the Szlachta (nobility) in the Grand Duchy of Lithuania. Achievements and shortcomings of pre-revolutionary historiography are identified. The research on this issue is divided into two stages. The first stage (16th–18th centuries) was characterized by genealogical and heraldic studies (Maciej Stryjkowski and Bartosz Paprocki, Kasper Niesiecki). The second stage (late 18th – 1st quarter of the 20th century) is represented by the works of Ivan Lappo, Matvei Lyubavsky, Fyodor Leontovich, Stanisław Ptaszycki, and others. It is concluded that pre-revolutionary historiography provided a rich material for research but missed aspects such as the reasons and legal regulation of the procedure for proving membership in the Szlachta, the tactics of judicial processes, and their impact on the society and culture of the Grand Duchy of Lithuania. Nevertheless, the pre-revolutionary period laid the foundation for further research on the problem of proving nobility, which remains relevant in the 21st century.

TRADITIONAL AND NON-TRADITIONAL DECORATIVE COATINGS OF JEWELLERY AND COSTUME JEWELLERY

A wide range of protective and decorative coatings and materials used in the manufacture of jewellery and costume jewellery is considered. It is shown that the use of certain coatings and technologies of their application or formation is determined by the materials used. The classification and scheme of using decorative coatings on the surface of the main groups of materials used in the manufacture of jewellery and costume jewellery is proposed. The coatings are divided into two main groups – traditional and non-traditional. Traditional coatings include coatings, the technology of formation and decorative properties of which have recently undergone significant modernisation. The non-traditional ones include relatively new decorative coatings, which have become widely used in the manufacture of jewellery and costume jewellery in recent decades. It is noted that the development of material science and technological base of jewellery industry leads to the emergence of new interesting coatings, which allows to significantly diversify the possi-bilities of jewellery creators.

The development of carbon nanostructured biosensors for glucose detection to enhance healthcare services: a review

In this review, the forefront of biosensor development has been marked by a profound exploration of carbon nanostructured materials for the specific application of glucose detection. Moreover, this progressive line of inquiry capitalizes on the distinctive attributes of carbon nanostructured materials such as carbon nanotubes, carbon quantum dots, and graphene which exhibit unique characteristics in the development of biosensor engineering design. It also enhanced analytical performances regarding the limit of detection, selectivity, sensitivity, and reproducibility towards glucose detection in biological samples. Most importantly, the strategic integration of carbon nanostructured-based biosensor architectures has played a significant role in advancements, characterized by heightened sensitivity, exquisite selectivity, and augmented stability in glucose detection processes. Furthermore, utilizing these advanced materials has engendered a transformative impact on electrochemical properties, propelling the biosensors to achieve rapid and precise glucose-sensing capabilities. The confluence of carbon nanostructures with biosensor technology has not only elevated the scientific understanding of glucose detection mechanisms. Still, it has also paved the way for miniaturized and portable biosensors. This transformative shift holds great promise for the realization of point-of-care diagnostics, representing a pivotal step towards durability and efficient glucose monitoring in health/medical care. These advancements emphasize the crucial role of carbon nanostructured-based biosensors in opening the way to a new avenue of superiority and effectiveness in diabetes management. Conclusively, the challenges and, in a forward-looking stance, the prospective futures of glucose biosensors anchored on carbon nanostructured frameworks were considered.

Research on the design and application of Analog-to-Digital converters

Abstract. In the modern digital era, the conversion of analog signals to digital data is a crucial process for a wide range of applications in industries such as consumer electronics, medical devices, and telecommunications. The accelerated evolution of digital technology is driving a surge in demand for high-performance analog-to-digital converters (ADCs). The paper presents a comprehensive analysis of analog-to-digital converters, emphasizing their types, applications, performance measurements, and most recent developments. In the paper, emphasis is placed on the mechanisms of different ADC architectures, such as Successive Approximation Register (SAR), Sigma-Delta (-), and Flash ADCs, and their respective strengths and weaknesses are evaluated. In terms of technique, it synthesizes and summarizes research results from multiple academic sources and technical papers. In addition to underscoring the pivotal concerns of ADC design, including power consumption, resolution, and sample rate, the research delves into novel approaches that leverage the use of advanced materials and techniques. The research results demonstrate the continued development of ADC technology and its critical function in improving the effectiveness and performance of digital systems.

A Case Study on Using the Concrete Cover Block in Steel Reinforcement Bar: Ghorahi Dang, Nepal

Cover block is one of the basic component on building structure like slab, column, beam, foundation. It is a multi- functionary engineering material. In maximum construction sites, bricks, stones, steel bars are used instead of cover block. This brings a lots of depraved consequences on building structures like lack of well spacing between surface and reinforcement bars, unbalance position of steel bars, reduce the lifespan of building and corrosion. Here, the main function of cover block is to reinforce the building structure by avoiding the corrosion on steel bar or avoiding the moisture with the steel bar, providing the resistive property, distributing an uniform load and managing space. In this way, the cover block is attached in a reinforcement bar in order to reinforce a building structure. When cover block was applied in a building structure, it made a building more durable as well as more attractive by maintaining the shape. This observation suggests that the use of cover block can contribute in strengthening a building structure and maintaining a position and space of a reinforcement bars as well as a structure. Key Words: Concrete cover block, Reinforcement bar, Potential failure of structure, Space maintaining, Corrosion activity.

Structure Engineering of Ga2O3 photodetectors: A Review

Abstract Deep ultraviolet (DUV) photodetectors play important roles in the modern semiconductor industry due to their diverse applications in critical fields. Wide bandgap semiconductor Ga2O3 is considered as one promising material for highly sensitive DUV photodetectors. However, the high responsivity of Ga2O3 DUV photodetectors always comes at the expense of its response speed. Material engineering for high-quality Ga2O3 materials can optimize the photoresponse performance but at the cost of much more complex process. Structure engineering can efficiently improve the performance of Ga2O3 photodetectors based on various physical mechanisms. Owing to the increased modulation probabilities, part schemes of structure engineering even alleviate the tough requirements on Ga2O3 material quality for high-performance DUV photodetectors. This article reviews the recent efforts in optimizing the performance of Ga2O3 photodetectors through structure engineering. Firstly, photodetectors based on Ga2O3 nanostructures and metasurface structures with nanometer size effect are discussed. In addition, junction structures of Ga2O3 photodetectors, which effectively promote carrier separation in the depletion region, are summarized based on a classification of Schottky junction, heterojunction, phase junction, etc. Besides, Ga2O3 avalanche photodiodes, offering ultra-high gain and responsivity, are focused as a promising prototype for commercialization. Furthermore, field effect phototransistors, based on which the scalability and low power performance of Ga2O3 photodetectors have been well proven, are analyzed in detail. Moreover, auxiliary-field configurations with extra tunable dimensions for Ga2O3 photodetectors are introduced. Finally, we conclude this review and discuss the main challenges of Ga2O3 DUV photodetectors from our perspective.

Renaissance Goo: Senses and Materials in Early Modern Apothecary Taxonomies and Soft Matter Science

This essay brings together research in the history of science and soft matter physics to consider how early modern Italian apothecaries organised and communicated their knowledge from the fourteenth to the seventeenth century through an “apothecary taxonomy.” This was based on a what we call a “hylocentric” classification scheme (from the Greek hyle = matter, material, stuff) founded on a tactile understanding of materials. We will investigate how the behaviour of medicines under deformation and flow – their “rheology” – is a previously underestimated organisational principle, and consider the specialist vocabulary these author-practitioners used to describe different liquid and liquid-like formulations. We will also suggest that the rheology of these formulations – which today falls under the domain of “soft matter science” – affected the material culture of apothecary shops, in the arrangement and selection of drug bottles and jars, which presented this knowledge visually to visitors and clients. That soft matter scientists organise the substances they study in similar ways to early modern apothecaries suggests the agency of materials in affecting human categorisations.

Layered nanoarchitectonics for condensed hard matter, soft matter, and living matter.

Nanotechnology has elucidated scientific phenomena of various materials at the nano-level. The next step in materials developments is to build up materials, especially condensed matter, based on such nanotechnology-based knowledge. Nanoarchitectonics can be regarded as a post-nanotechnology concept. In nanoarchitectonics, functional material systems are architected from nanounits. Here, this review would like to focus on layered structures in terms of structure formation. The unit structures of layered structures are mostly two-dimensional materials or thin-film materials. They are attractive materials that have attracted much attention in modern condensed matter science. By organizing them into layered structures, we can expect to develop functions based on communication between the layers. Building up layered functional structures by assembling nano-layers of units is a typical approach in nanoarchitectonics. The discussion will be divided into the following categories: hard matter, hybrid, soft matter, and living object. For each target, several recent research examples will be given to illustrate the discussion. This paper will extract what aspects are considered important in the creation of the layered structure of each component. Layering strategies need to be adapted to the characteristics of the components. The type of structural precision and functionality required is highly dependent on the flexibility and mobility of the component. Furthermore, what is needed to develop the nanoarchitectonics of layered structures is discussedas future perspectives.

PECULIARITIES OF THE KEY IMAGES CONVEYING OF А.S. PUSHKIN’S POEM “TO THE SLANDERERS OF RUSSIA” IN ENGLISH TRANSLATIONS

The article deals with the peculiarities of rendering the key images of A.S. Pushkin’s poem “To the Slanderers of Russia” in the English translations. The research aims at comparative analysis of the key images rendering and stylistic features of the poem. The research material comprises three English translations. The article analyses the transformation of the text and its key images. In particular, the article compares the semantic fields of the original lexemes with their English equivalents. It is defined how the translator’s selection of a particular translation unit affects the tonality of the work. Moreover, the impact of the historical context and the translators’ personal perception on the translated text is analysed. The article deals with the problem of transferring realities when translating a poetic text. The study applies elements of etymological, comparative-historical and comparative analyses. The images conveyed are actively undergone various translational transformations. The transferred images are actively subjected to various translation transformations.

Corporate Technology for the Implementation of an Automated System: Functional, Technological and Methodological Aspects

The purpose of the study is to form a methodological justification for the pedagogical model of the individual trajectory of professional development of bachelors and masters for the implementation of the stages of creating an automated system based on the principles of continuity and experimental verification of its application in the educational process of the university in accordance with the requirements of IT departments, vendors and employers. It is shown that there is a gap between the socio-economic order for the training of IT specialists with high professional competence in the field of information systems and the insufficient level of targeted formation of their readiness to implement the stages of creating automated systems. In addition, the lack of methods and practical recommendations for the implementation of such systems in the context of maximum preservation of corporate standards and taking into account the requirements of Russian legislation, as well as specialists competent in these matters, determined the feasibility of conducting the study in two aspects - functional-technological and pedagogical.Methods and materials. The key methods are structural-functional and process modeling, interactive methods of organizing the educational process (project method, etc.). The research materials include a functional model for developing a corporate technology for implementing an automated system in the form of a function tree.Results. The results present a model of causes and factors determining the success of the projects for the implementation of the automatization systems. The role of the factor “qualification of the performing team” and the possibilities of the educational environment of the university to influence this factor are considered. The pedagogical aspect of the research problem is determined by the methodological justification for conducting students’ project work within a number of disciplines for training bachelors and masters in the field of “Applied Informatics”. The description of the structure and requirements for students’ projects gives an idea of the level of formed competencies, their consistency with the work functions of specialists in the field of information systems.Conclusion. At this stage of work on the research problem, its dual nature was determined. On the one hand, modern IT projects require their own technologies and management methodologies, which should change from project to project, so it is important to have practical recommendations for the development of corporate technology for the implementation of an automated system. On the other hand, one of the success factors of the project for the implementation of an automated system is the “Project Implementation Team”, its level of qualification. This factor is successfully determined and influenced by educational institutions responsible for training specialists in this field. In this direction, the project method plays a key role. It ensures the development of communication skills, the ability to independently pose a problem and develop a way to solve it together. Methodological aspects and practical results, generalizing the pedagogical model for training bachelors in the field of creating automated systems presented in the paper, as well as the development of corporate technology for the implementation of information systems, were reflected in three electronic multimedia educational publications: “Portfolio of Software Engineering Projects”, “Theory and Practice of IS Implementation”, “Theory and Practice of IS Maintenance”.

Pathways to Carbon Neutrality in Civil Engineering

Abstract. With the development of the global economy and trade exchanges worldwide, urban infrastructure and industrial development have become part of the competition among countries. However, the construction industry and the production of chemical materials emit a large amount of carbon dioxide, leading to the continuous deterioration of the environment, so it is necessary to effectively reduce emissions. As a synonym for global emission reduction, carbon neutrality plays an important role in different industries, especially in civil engineering. In this paper, we start with building materials and green construction to explore the realization of carbon neutrality at the source and center of carbon emission in civil engineering. Firstly, we introduce the low-carbon production technologies of cement and steel, including calcium recycling and membrane separation technology in the cement industry, high-temperature combustion technology and carbon capture technology in steel industry. Then, we take renewable concrete as an example to discuss the emission reduction path of green building materials. Finally, it outlines how to carry out green construction, introduces assembly carbon reduction technology and energy integration system, and demonstrates the possibility of this green construction program in the case of "T&A House".