Composite Element Research Articles

Effect of Al content on the microstructure and mechanical alloying behavior of AlCoCuMnNi and Al0.25CoCuMnNi high entropy powders

The concept of high entropy alloys (HEAs) is an emerging subject in materials science and engineering. The presence of at least four elements in equiatomic or near equiatomic composition in HEAs has led to superior properties and vast unexplored alloying space. In this study, we investigated two new HEA powders, AlCoCuMnNi and Al0.25CoCuMnNi, by subjecting mechanically milled (MM) powders to a series of analyses over a 60 h ball milling process. It was found that alloying starts after 20 h of MM and after 45 h, full elemental integration into the host lattice was detected. Meanwhile, further milling to 60 h can cause powder contamination. The High-Resolution Transmission Electron Microscopy (HRTEM) results validated the XRD findings and provided further insights into the substantial influence of Al content on the microstructure and the extent of amorphization within the milled powders. Differential Thermal Analysis (DTA) analysis on the MM powders showed one exothermic peak for AlCoCuMnNi and one for Al0.25CoCuMnNi at high temperatures, which may suggest the formation of the BCC or second FCC phases for these alloys. The results confirmed the significant influence of the increased Al content on increasing both the lattice constant and lattice strain while decreasing thermal stability of the investigated MM powders. The present results provided insights needed for consolidation of such HEA powders.

Специфіка фейлетонів журналу «Кіно» за 1926 рік

The purpose of the article is to find out the specifics of the feuilletons printed in the magazine "Kino" for 1926.Methodology.Descriptive, systematic methods, methods of analysis, synthesis, statistical methods, and hermeneutic methods were used in the research process. Information necessary for the coverage of the topic of the scientific article was recorded using the descriptive method. The content and form of feuilletons were comprehensively analyzed using the systematic method. The method of analysis made it possible to single out compositional techniques and elements, means of psychologism from the texts. The method of synthesis presents the functional features of the form-content elements. Thanks to the hermeneutic method, original interpretations of the analyzed texts are offered.Thanks to the statistical method, the quantitative ratio of the used compositional elements and techniques, psychological tools for modeling the images of the characters or the collective image of the audience was clarified.Research results. In 1926, 4 feuilletons were printed in the magazine "Kino", which discussed current problems, the emergence of which was caused by the specifics of the development of cinematography at that time, determined by cultural and socio-political factors.Conclusions. The topics and problems of the feuilletons are revealed more deeply with the help of creolization of the texts, in particular, it is about the use in all feuilletons of illustrations, which are characterized by multifunctionality, with text quotes. The plot of feuilletons, the compositional features of which are the division of texts into parts, the use of compositional framing, the compositional technique "story within a story", film advertising, and descriptions, is presented with the help of either extra-diegetic or homodiegetic narrators, as well as due to their contamination. To model the figurative system of feuilletons, the authors used various means of psychology, visual, sound, olfactory details, and artistic means that give feuilletons dynamism, and expressiveness, and increase the humorous and satirical effect.

Microstructural evolution and hydrogen content and their effect on properties of TiB2/Al-Li-X composites with different Li contents

The content and proportions of the major solute elements in aluminum matrix composites are critical to the microstructure and properties of the material. This paper uses a stepwise method based on ultrasonic in-situ casting technology to prepare TiB2/Al-Li-X composites with different Li contents (0.5–3.0 wt%). The composites' microstructure morphology, precipitates, hydrogen content, and mechanical properties were tested and analyzed. The results showed that with the increase of Li content, the number of θ′ phases decreases, the number of δ′ phases increases, while the number of T1 phases increases and then decreases, and the TiB2 particles promote the precipitation of T1 phases at low Li content; meanwhile, the hydrogen content keeps increasing, and the grain size decreases and then increases. The increase of the T1 phase and the decrease of grain size enhance the strength of the composites, while the increase of δ′ phase and hydrogen content increase the hardness but decrease the plasticity. When the Li content is around 1.5 wt%, the grain size is minimized, the TiB2 particles are fine and dispersed, the yield strength reaches the maximum value of 166.9 MPa, and the mechanical properties are relatively balanced.

Stress stateofa composite tractive element with cable rigidity variable over length considering bending on a drum with curved generatrix

Purpose. Establishment of dependencies for parameters of a stress-strain state of a composite tractive element taking into account bending of a rope with cable rigidity variable over length on a drum with a curved generatrix. Research methodology. Development of a method for calculating the influence of a complex of factors on a stress-strain state of a rope by constructing and solving a model of a stress-strain state of a composite tractive element with cable tensile rigidity variable over length, cable base breakages and a non-cylindrical drum shape, using the methods of mechanics of layered composite materials with soft and hard layers. Findings. Analytical dependencies are obtained in a closed form and allow determining the maximum quantitative indicators of a stress-strain state of a rope of a combined structure with a broken cable, rigidity different from the main cables and variable along rope length in a straight rope part and in a part of interaction with a curved drum of a hoisting machine. Analytical dependencies are established for determining the maximum angles of rubber shear between cables, which allows determining the dangerous tangential stresses in a tractive element for cases of flat rope tension, rope bending on a convex drum, and bending on a convex drum of a rope with cables of reduced tensile rigidity. The results of solving the problem of determining the distribution of forces in a rope with cables of different rigidity by the developed method absolutely coincide with the only possible distribution of forces in a sample of three cables, which allows considering the developed algorithm reliable to describe the mechanism of redistribution of forces between cables with different tensile rigidity, including in the event of cable breakage, and the obtained results are reliable. Scientific novelty. A method of calculating the influence of a complex of factors on a stress-strain state of a rope is developed. The dependencies of parameters of a stress-strain state of a composite tractive element are established, taking into account rope bending, which has cable base breakages and cable rigidity variable over length, on a drum with a curved generatrix. Practical significance. A method for determining the indicators of a stress-strain state of a composite tractive element, which has cable base breakages and cable rigidity variable over length, including for bending on a non-cylindrical drum, is developed. This makes it possible to increase the operational safety of a composite tractive element in hoisting and transporting machines, in particular at significant hoisting heights, and also contributes to justifying the use of a rope design as a stay rope in capital structures.

Automatic generation of 3D micromechanical finite element model with periodic boundary conditions to predict elastic properties of bamboo fibre-reinforced composites

This study presents an automatic algorithm to generate a three-dimensional (3D) micromechanical finite element (FE) model to predict elastic behaviours of biocomposites reinforced with unidirectional (UD) continuous natural fibres such as bamboo fibres. The developed algorithm constructs a virtual FE framework by generating stochastic Representative Volume Elements (RVEs) of fibre-reinforced composites incorporating random fibre arrangement and random assignment of fibre radii. It also applies various loading scenarios and periodic boundary conditions to simulate elastic behaviours accurately. The algorithm generates 3D periodic RVEs by introducing boundary and corner fibres. All the 3D RVE models, representing different fibre-reinforced composites, various loading cases, and periodic boundary conditions, are automatically created using Python scripting with the Abaqus FE solver. The accuracy of the algorithm and virtual FE test model is validated through comparisons with analytical models and experimental results. The effects of different types of fibre radius assignment, fibre volume fraction, and fibre periodicity on the prediction of effective elastic properties are investigated. The study also establishes correlations between all elastic constants of bamboo fibre-reinforced composites and the fibre volume fraction.

Interference logic elements based on a Y-shaped defect photonic crystal

We discuss prospects of using a photonic crystal with a Y-shaped defect for the implementation of interference logic elements. By the numerical modeling we demonstrate that such photonic-crystal elements can implement logic operations such as "AND", "OR", "XOR" and "NOR". Particular attention is given to demonstrating the possibility of cascading such elements with the aim of synthesizing composite interference logic elements capable of implementing other logic operations.

Female Subjectivities in the Words, Music, and Images of Progressive Metal

Heavy metal scholarship affirms the genre to be dominated by male performers and points to a preponderance of patriarchal values and hypermasculinity, with performances contributing to an aesthetic production of misogyny, power, and intensity. The notion of heavy metal as a hegemonic discourse has been queried, however, by recent scholars who reveal metal to support a range of gendered and sexualized subjectivities. This paper examines how a specific metal vocalist—Tatiana Shmayluk (of the Ukrainian band Jinjer)—navigates the discourse of progressive metal to challenge hegemonic norms and create space for alternative female subjectivities. Jinjer’s defiance of genre boundaries and Shmayluk’s metal vocal expression emerge through a multi-faceted dialogue with an array of cultural references. To illuminate the unique blend of referentiality and creative expression within Jinjer’s work, this article offers analyses of three music videos: “I Speak Astronomy,” “Perennial,” and “Pit of Consciousness.” With the aim of understanding how Shmayluk navigates the discursive space of metal music, the selected songs are situated in relation to the subgenres to which they refer, and specifically to male-fronted metal bands that mobilize similar thematic materials. The close readings of these music videos are grounded in the existing analytic literature on metal music, with consideration of genre-based compositional, stylistic, and expressive elements to unveil Shmayluk’s challenges to the constraints upon “femininity” in metal music.

A Set of Questions for a Field in Motion: Susan Leigh Foster’s “Choreographies of Protest” and Dance Studies in Theatre Journal

Abstract: In her landmark essay “Choreographies of Protest,” Susan Leigh Foster articulated the central concerns of the (at the time) developing field of dance studies. Foster’s following analysis, embedded in her argument about the compositional elements of social action, advanced core dance studies methodologies. On the occasion of the 75th anniversary of Theatre Journal , this essay revisits “Choreographies of Protest,” published in the October 2003 issue, and considers its significance to the fields of theatre, performance, and dance studies. Foster’s famous guiding questions that appeared in this essay, and which foregrounded real-world actions of the body, served to define the methodological approach and possibility of dance studies as a field, both concretizing the queries that previous scholarship had addressed and proposing what might be examined in years to come. In so doing, these seemingly straightforward queries, and the answers they elicit, begin to argue for dance studies as an essential discipline to the humanities, a way of understanding both human experience and human relations.

Logos of South Asian Countries: A Visual Aesthetic and Symbolic Significance

A national logo is a visual representation of a country, and it signifies the most powerful visual language of any country in the world. All the countries have their own logo to represent their country in visual form. In the context of each country in South Asia, a national logo is categorized as a national emblem. The national emblems of South Asian countries have different and unique meanings and are made with different cultural, religious, natural, and historical motifs and shapes. The main objective of this paper is to identify the visual aesthetic and symbolic significance of the national emblems of each South Asian country. The visual aesthetic contains elements of composition, color, shapes, and the essential rules of a logo, while the symbolic significance contains the symbolic meaning of each motif used for the entire logo of a South Asian country. This study finds that a country's culture, religion, and history should not be disconnected from the national emblem because the national emblem creates unique values for a country. A national emblem is like a mirror of a country, which represents the appropriate visual symbol of a country. This study is an analytical study based on qualitative method.

Engineering novel optical arrays using a multi-focusing complex sinusoidal grating-based spiral zone plate

This paper showcases a novel composite diffractive element that can be finely tuned to generate a myriad of stunning beam patterns and structures. Specifically, we have redesigned the spiral zone plate by incorporating a complex sinusoidal grating into its structure, which has considerably expanded the range of effective parameters available to engineer various shapes and structures of light beams. Furthermore, this element functions as a multi-focusing component, enabling the creation of optical arrays of diverse forms, ranging from basic spots and grids to intricate and innovative beam shapes. Our research involves extensive mathematical analysis and associated simulations, as well as experimental validation of the mathematical findings.

Morphological, Structural, and Optical Features of Thermally Annealed Slag Powders Generated from the Iron and Steel Industry: A Source of Disordered Iron Oxide Composites

Steel slag waste produced by the steel industry accumulates in open areas or is disposed of in landfills, causing harm to the environment and human health. Valorizing steel slag through comprehensive data analysis is imperative and could add value to the product with respect to energy conversion and storage applications. This study investigated the morphological, structural, and optical characteristics of a thermally annealed steel slag composite generated from iron and steel factories. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Raman spectroscopy, and UV–visible spectrophotometry were subsequently used to evaluate the impact of thermal treatment on the morphology, structure, elemental composition, and optical properties. It was found that the pre-treated slag composites contained a variety of irregular grain sizes and microscale fragments, primarily composed of C (18.55%), O (50.85%), and Fe (29.41%), with lower amounts of Mg (0.31%), Si (0.44%), and Ca (0.44%), indicating the natural formation of a disordered iron composite. Thermal treatment at different temperatures (300 °C, 600 °C, and 900 °C) increased the grain density and clustering, resulting in denser two-dimensional microstructures at 900 °C. Additionally, XRD and Raman analyses of both untreated and thermally treated slag composites revealed the presence of a disordered iron oxide composite, including (Fe3O4), hematite (α-Fe2O3), and maghemite (γ-Fe2O3) phases. A significant increase in optical absorbance was also observed after annealing at 600 °C, highlighting the successful optimization of the elemental composition of the slag composite. A band gap energy of approximately 2.2 eV was obtained from this optimization at 600 °C. The optical conductivity of the composite reached 2.1 × 106 S−1 at 600 °C, which indicates an enhancement in charge transfer among the optimized chemical elements in the waste composite. These findings suggest an optimization method for novel composites derived from steel slag waste, indicating its potential as a low-cost material for energy storage systems (batteries, supercapacitors, and fuel cells) and optoelectronic devices.

Identification of Dynamic Vibration Parameters of Partial Interaction Composite Beam Bridges Using Moving Vehicle

The vibration response of a partial composite beam bridge under the influence of moving vehicular loads was investigated. Due to the coupling effect between the vehicle and the bridge, the vibration information of the vehicle encompassed the vibration information of the bridge. Consequently, the dynamic response of the vehicle could be utilized to extract the dynamic information of the composite beam. A moving mass-spring-damping system and composite beam elements considering interfacial slips were used for the interaction vibration of a vehicle-composite bridge. A finite element program for the interaction vibration analysis of the vehicle-composite beam bridge was developed. The program was used to extract the vibration information of the composite beam bridge by analyzing the vehicle displacement, velocity, and acceleration in the interaction vibration of the beam and the vehicle. Taking the Hangzhou Jiubao Bridge as the engineering background, the influences of structural parameters such as shear stiffness of connections, prestress magnitude, as well as vehicle parameters, including vehicle stiffness, damping, and mass, on frequency identification were analyzed. Furthermore, the influences of road roughness, disturbance force generated by vehicle random vibrations, and interference signals generated by signal transmission on frequency identification of the bridge were investigated.

Dynamic Interactive Design of Graphic Design Elements Based on Image Feature Extraction Algorithm

Abstract This paper first analyzes the use and expression of line and surface, color, and text as graphic design composition elements. Secondly, it analyzes the relationship between interaction design and other disciplines and constructs a dynamic interactive design model for graphic design. Then, the features of color, texture, shape and spatial relationship of the image are extracted by the feature extraction algorithm, and the gesture recognition algorithm is used to determine the operation requested by the user and execute it. Finally, data analysis was conducted on 32 randomly selected students from the design school of University H who applied the dynamic interactive design model. The results show that the dynamic interactive design has the highest rating in terms of smooth operation, with an average score of 6.893, and the lowest rating is in terms of low learning cost, with an average score of 5.087. This shows that the dynamic interactive design model of graphic elements can improve the smoothness of operation, thus improving the dynamic interactive experience of students and providing direction for the development of the field of graphic design.

Shock Hugoniot of an equiatomic high-entropy alloy NbMoTaW up to 143 GPa

The equations of state and phase stabilities of high-entropy alloys (HEAs) under high-pressure and high-temperature conditions are of paramount importance for engineering applications. However, few reports exist on the high-pressure–temperature properties of the HfNbMoTaWV HEA system. Herein, we synthesized a NbMoTaW HEA using the vacuum arc melting method and measured its Hugoniot up to 143 GPa and ∼6200 K. A linear relationship [US = 2.61 (7) + 1.59 (5) UP] between the shock (US) and particle (UP) velocities was observed for UP > 0.7 km/s, suggesting that the NbMoTaW HEA is likely stable within the pressure–temperature range of the current study. Using the Debye–Mie–Grüneisen model and Birch–Murnaghan equation of state (EOS), we discussed the EOS of the NbMoTaW HEA. The bulk modulus (K0) and its pressure derivative (K0′) were determined to be 238 GPa and 3.3, respectively. We also found that the Hugoniot compression curve of the NbMoTaW HEA could be evaluated using the mixture rules with the Hugoniot data of the compositional elements.

Detection of Xylene Using Ni(OH)2-Enhanced Co3O4 Nanoplate via p–n Junctions

This study reports a novel Ni(OH)2/Co3O4 heterostructured nanomaterial synthesized through a simple two-step hydrothermal method combined with subsequent heat treatment. The Ni(OH)2/Co3O4 heterostructured nanomaterial showed excellent performance in the detection of xylene gas. XRD, SEM, and EDS characterized the crystal structure, microstructure, and composition elements of Co3O4 and Ni(OH)2/Co3O4, and the gas sensing properties of the Co3O4 sensor and Ni(OH)2/Co3O4 sensor were systematically tested. The test results indicate the Ni(OH)2/Co3O4 sensor has an optimal operating temperature of 175 °C, which is 10 °C lower than that of the Co3O4 sensor; has a response of 14.1 to 100 ppm xylene, which is 7-fold higher than that of the Co3O4 sensor; reduces the detection limit of xylene from 2 ppm to 100 ppb; and has at least a 4-fold higher response to xylene than other gases. The Ni(OH)2/Co3O4 nanocomposite exerts the excellent catalytic performance of two-dimensional nanomaterial Ni(OH)2, solves the deficiency in the electrical conductivity of Ni(OH)2 materials, and realizes the outstanding sensing performance of xylene, while the construction of the p–n heterojunction between Ni(OH)2 and Co3O4 also improves the sensing performance of the material. This study provides a strategy for designing high-performance xylene gas sensors using two-dimensional Ni(OH)2 materials.

The lateral confinement effect on the interfacial crack in hybrid composites under uniaxial compression

The effect of hybridization on the interface crack growth along the fiber is predicted from numerical and analytical modelling approaches. A three-phase hybrid composite representative volume element (RVE) with an adjustable hybrid ratio and an initial interfacial crack is modelled. The fracture parameters and composite strength are computed from finite element analysis using VCCT approach in Ansys Workbench. A fracture energy-based mathematical model with a steady state crack growth is implemented to compute the hybrid composite splitting failure strength. The results show an enhancement in the compressive splitting strength with hybridization due to lateral confinement effect on the interfacial crack.

Zn-modified In2O3 nanoparticles: Facile synthesis, characterization, and selective cytotoxicity against human cancer cells

Oxide nanoparticles (NPs) have attracted considerable interest owing to their unique characteristics and possible applications, including gas detection, bioanalytical sensing, catalytic, and biomedical. The present work was designed to explore the effect of varying amounts (2.5 %, 5 %, and 7.5 mol%) of Zn-doping on the properties and selective anticancer efficacy of In2O3 NPs. The precipitation process was applied to prepare pure In2O3 NPs and Zn-doped In2O3 NPs. XRD, TEM, SEM, EDX, XPS, UV–Vis, and PL techniques have been employed to investigate the physicochemical properties of NPs. The XRD analysis revealed that the crystallite of the In2O3 lattice was slightly changed with the addition of Zn ions. TEM and SEM images displayed that the reduction of size of In2O3 NPs was increased with increasing Zn concentrations. The composition elements and distribution of Zn dopants within In2O3 NPs were further confirmed by EDX and XPS techniques. Based on the UV–Vis study, increasing the Zn amount improved the gap energy of In2O3 NPs by shifting edge absorption peaks to lower wavelengths. Moreover, PL spectra show that the intensity of In2O3 NPs decreased with increasing the Zn amount. The biological results indicate that the Zn-doped In2O3 NPs exhibited a significant increase in cytotoxicity with Zn doping increased against MCF-7 and HCT116cells while they have excellent biocompatibility with normal human cells (HUVECs). These results suggest that these NPs hold promise as a novel therapeutic approach in cancer treatment. This study requires more research into the biological applications of Zn-doped In2O3 NPs.

Microwave plasma-produced Al/Al2O3 microparticles as precursors for high-temperature high-strength composites

Microwave plasma-produced Al/Al2O3 microparticles as precursors for high-temperature high-strength composites

Selective Laser Melting of Non-Weldable Nickel Superalloy: Microstructure, Cracks and Texture

Additive manufacturing, particularly selective laser melting, presents exciting possibilities for fabricating components from high-temperature nickel-based superalloys. Controlling microstructural features and minimizing defects in fabricated specimens are critical challenges. This study explores the influence of process parameters on microstructure and defect formation in directionally solidified nickel-based superalloy specimens. We conducted a comprehensive analysis of selective laser melting process variables, including interdendritic spacing, crystallization times, and volumetric energy density. Electron backscatter diffraction analysis was employed to assess the feasibility of obtaining a directional structure in single-crystal nickel-based heat-resistant alloy specimens using selective laser melting. The study shows a significant correlation between reduced interdendritic spacing and increased defect formation. Longer crystallization times and higher volumetric energy density lead to decreased defect volumes and sizes. Electron backscatter diffraction analysis confirms the maintenance of preferential growth direction across subsequent layers. Our research underscores the importance of optimizing selective laser melting parameters, balancing refractory elements in alloy composition, and adopting strategies for enhancing crystallization times to minimize structural defects. This comprehensive approach ensures both heat resistance and minimal defects, facilitating the production of high-quality components. These findings contribute to advancing selective laser melting applications in critical industries like aerospace and power generation, where heat-resistant materials are paramount.

Investigation of Long-Term Corrosion of CoCrMoW Alloys under Simulated Physiological Conditions

The corrosion resistance of two cast CoCr-based alloys with different amounts of chromium and with different alloying elements in the bulk composition of the alloy was assessed. In this study, we investigated the corrosion behavior of Co21Cr8Mo7W and Co29Cr7W by open-circuit potential (OCP), potentiodynamic polarization (PP) and electrochemical impedance spectroscopy (EIS) in 0.1 M phosphate buffer solution (PBS) at 37 °C with long immersion times. After 1000 h of immersion, the corrosion current density (icor), estimated from anodic polarization tests, was lower for the Co21Cr8Mo7W (i.e., 49 nA cm−2) alloy compared to the Co29Cr7W alloy (180 nA cm−2). As regards the corrosion potential (Ecor), a greater value was observed for Co21Cr8Mo7W (i.e., −59 mV vs. Ag/AgCl) compared to Co29Cr7W (i.e., −114 mV vs. Ag/AgCl). Microstructure analysis before and after immersion revealed the formation of a more compact passive film on the Co21Cr8Mo7W alloy, suggesting superior corrosion resistance compared to Co29Cr7W. These findings suggest better corrosion resistance for the film formed on the alloy containing lower amounts of Cr and two alloying elements, Mo and W. These results are promising in terms of medical applications because they open the door to new strategies for obtaining alloys with lower chromium content and with more protective anti-corrosion properties.