Structural Materials Research Articles

Bearing capacity of plates under distributed load

In the current conditions of rapiddevelopment of the construction industry, there is aneed to use high-strength concrete, createinnovative structural systems and study effectivebuilding materials and structures. One of the mosteffective materials of the new generation is steelfiber concrete, which, due to its exceptionalproperties, is actively used in modern construction.Studies of bearing capacity [4, 9, 15] are animportant direction in construction engineering, asthey make it possible to assess the operationalcapabilities of slabs and develop effective methodsfor increasing their bearing capacity, deformabilityand resistance to cracking.As part of the work, comprehensiveexperimental studies were conducted to assess thestress-strain state of slabs with different types ofreinforcement. Reinforced concrete and fiberconcrete slabs were studied in order to comparetheir behavior under load depending on the methodof reinforcement.The results of the experiments showed the highefficiency of fiber in improving the strengthcharacteristics of slabs. Steel fibers contribute toincreasing the strength of structures and reducingthe manifestations of cracking.Thus, the choice of the type of dispersedreinforcement depends on the specific operationalrequirements of the structure. The use of dispersedreinforcement in construction significantlyincreases the strength characteristics, crackresistance and durability of structures, includingslabs, making them more reliable and resistant tovarious types of loads, including operational loads

Effect of the Heterogeneity of Coal on Its Seepage Anisotropy: A Micro Conceptual Model

Coal is a typical dual-porosity structural material. The injection of CO2 into coal seams has been shown to be an effective method for storing greenhouse gasses and extracting coal bed methane. In light of the theory of dual-porosity media, we investigate the impact of non-homogeneity on seepage anisotropy and examine the influence of CO2 gas injection on the anisotropy of coal and the permeability of fractures. The results demonstrate that under constant pressure conditions, coal rock has the greatest permeability variation in the direction of face cleats and the smallest changes in the direction of vertical bedding. The more pronounced the heterogeneity, the more evident the change in permeability and the less pronounced the decreasing stage of permeability. Additionally, the larger the diffusion coefficient is, the less pronounced the permeability change. The change in permeability is inversely proportional to the size of the adsorption constant and directly proportional to the size of the fracture. As the matrix block size increases, the permeability also increases, whereas the decrease in permeability becomes less pronounced. The findings of this study offer a theoretical basis for further research into methods for enhancing the CO2 sequestration rate.

Effect of Heat Treatment on the Microstructure and Property of Metastable β Titanium Alloy.

TB18 is a newly developed high-strength metastable β-titanium alloy, commonly used in aerospace structural materials, which demands high mechanical performance. By altering the alloy's microstructure, heat treatment can affect its mechanical characteristics. The alloy was solution treated for one to four hours at 870 °C in order to examine the impact of solution treatment duration. Using X-ray diffraction (XRD) and scanning electron microscopy (SEM), the effects of solution treatment time on the β-phase grain size and its effect on stress distribution during tensile testing were examined. The findings showed that stress concentration during the tensile process was successfully decreased by refining the β-phase grain size. Sample solutions treated for two hours at 870 °C were then aged at various temperatures (510 °C, 520 °C, 530 °C, and 540 °C) to examine the impact of aging temperature. While the mass proportion of the α-phase first climbed and subsequently declined, reaching its maximum at 530 °C, the size of the α-phase increased monotonically as the aging temperature increased. The varies of mass fraction is associated with how the aging temperature affects α-phase nucleation. Tensile studies on TB18 alloy aged at various temperatures showed that while the alloy's ductility reduced, its strength increased as the aging temperature rose. The Hall-Petch relationship explains this tendency.

Analysis of Vibration Energy Harvesting Performance of Thermo-Electro-Elastic Microscale Devices Based on Generalized Thermoelasticity

Piezoelectric material structures with an excellent mechatronic coupling property effectively promote self-power energy harvesting in micro-/nano-electro-mechanical systems (MEMS/NEMS). Therein, the characteristics of the microscale and multi-physical aspects effect significant influence on performance, such as attaining a fast response and high power density. It is difficult to use the classical mechanical and heat conduction models to effectively explain and analyze microscale physical field coupling behaviors. The purpose of this study is to develop the piezoelectric thermoelastic theoretical model, firstly considering the non-uniform physical field. The generalized equations governing thermo-electro-elastic vibration energy harvesting in a microbeam model were obtained based on Hamilton’s principle and the generalized thermoelastic theory was developed by considering thermopolarization and thermal hysteresis behavior. After that, the explicit expressions for voltage and output power were derived using the assumed-modes method; meanwhile, effects such as the piezo-flexoelectric aspect, size dependence, etc. are discussed in detail. It was found that thermal and microscale effects significantly promote the voltage and output power. The research is also helpful for the design and optimization of self-powered and high-performance micro/nano devices and systems.

Pengembangan Modul Pembelajaran Pengantar Studi Islam: Studi pada Mahasiswa STAI Ali bin Abi Thalib Surabaya

This study aims to develop a learning module for the course Pengantar Studi Islam (Introduction to Islamic Studies) at the Ali bin Abi Thalib Islamic College (STAI) Surabaya, focusing on the sources of Islamic teachings: the Qur'an, Sunnah, Ijma', and Qiyas. The method used is Research and Development (R&D) with the Rowntree development model, which involves three stages: planning, development, and evaluation. Data were collected through expert validation, student questionnaires, and formative evaluation. The results of the study show that the developed module is valid, with an average score of 94% from content experts and 95.5% from language experts. It was also deemed very practical by students, with an average score of 82.82%. The module has proven to meet learning needs by providing structured material, communicative language, and relevant exercises. Suggestions from validators and students were implemented to enhance the quality of the module, making it more suitable for the learning context. The conclusion of this study indicates that the developed PSI learning module is valid, practical, and feasible for use in improving the quality of learning. This research is expected to serve as a reference for the development of similar teaching materials in the future.

Ontology for smart 4D printed material systems and structures synergically applied with generative artificial intelligence for creativity promotion

Abstract This study presents a versatile ontology for describing all kinds of smart or stimuli-responsive 4D printed material systems and structures. The different components of the ontology, namely: initial geometry and shape, shape-morphing principle(s), triggering stimuli, intermediate/final geometry and shape, 4D material and printing or additive manufacturing technology, are enumerated and classified. Accordingly, a codification system for schematically illustrating the actuation cycle of 4D printed material systems and structures, and shape-morphing devices in general, is proposed. The systematic application of the ontology to a relevant set of examples helps to demonstrate its utility and adaptability to many different types of 4D printed objects. It demonstrates that the ontology and codification schemes developed in this research can serve a comprehensive classification tool for the emergent field of 4D printing. It is the first ontology capable of representing the multiple actuation steps of complex 4D printed devices and actuators, in which several metamorphoses may be achievable, due to combinations of different shape-morphing principles and triggering stimuli. To this end, a single line of code is required. A glossary is provided to support its implementation and application. Besides, the usability of the ontology and related codification by a generative artificial intelligence (AI) for supporting engineering design tasks is explored and validated through a set of examples and an industrial use case. This work is expected to provide a universal language to facilitate the communication in the 4D materials and printing field, as well as a synergic generative AI-based methodology for creativity promotion linked to innovative smart 4D printed material systems and structures.

Feminist Photobooks in 1970s Italy

Abstract From the beginning of the twenty-first century, the expression photobook has proven highly successful in the wake of a rich series of studies, festivals, workshops, fairs, and publishing initiatives. The term photobook has, however, often been used to indicate, without much distinction, different types of photographic books that do not necessarily share aesthetic, political, or social aims, generating misleading perspectives on the genre. In order to examine the history of feminist photobooks in Italy in the 1970s, this article analyzes both the material and symbolic structures of these books as well as the contexts of their production and circulation, the artists’ careers, and their relationship to Italian neofeminism. Through a selection of books, the article offers case studies that can be considered significant examples of the relationship that can be considered significant examples of the relationship between photography, artist’s books, and feminist politics in the specific context of Italy in the 1970s.

A Review of Additive Manufacturing of Biodegradable Fe and Zn Alloys for Medical Implants Using Laser Powder Bed Fusion (LPBF).

This review explores the advancements in additive manufacturing (AM) of biodegradable iron (Fe) and zinc (Zn) alloys, focusing on their potential for medical implants, particularly in vascular and bone applications. Fe alloys are noted for their superior mechanical properties and biocompatibility but exhibit a slow corrosion rate, limiting their biodegradability. Strategies such as alloying with manganese (Mn) and optimizing microstructure via laser powder bed fusion (LPBF) have been employed to increase Fe's corrosion rate and mechanical performance. Zn alloys, characterized by moderate biodegradation rates and biocompatible corrosion products, address the limitations of Fe, though their mechanical properties require improvement through alloying and microstructural refinement. LPBF has enabled the fabrication of dense and porous structures for both materials, with energy density optimization playing a critical role in achieving defect-free parts. Fe alloys exhibit higher strength and hardness, while Zn alloys offer better corrosion control and biocompatibility. In vitro and in vivo studies demonstrate promising outcomes for both materials, with Fe alloys excelling in load-bearing applications and Zn alloys in controlled degradation and vascular applications. Despite these advancements, challenges such as localized corrosion, cytotoxicity, and long-term performance require further investigation to fully harness the potential of AM-fabricated Fe and Zn biodegradable implants.

A Methodology of Structural Incorporation for Model Transfer and Construction: The Case of Malthus’ and Darwin’s Models of Population

Abstract This paper proposes a methodology to investigate how the conceptual structure of a model may have borrowed from an already existing model in a different field. From a reverse perspective, it amounts to hypothesizing that an already existing model was somehow transferred to a new field and incorporated into a newly constructed model with the purpose of explaining some additional phenomena. We use two well-known theoretic models, Robert Malthus’ model of human population and Darwin’s model of organism population included in the theory of evolution by natural selection, to exemplify this “incorporation of a conceptual structure” methodology. By highlighting how the conceptual structure of Malthus’ model actually sits within that of Darwin’s model, we show how Darwin’s model may have been constructed, on the one hand, and how Malthus’ model may have been transferred, on the other hand. In order to show how the construction and transfer occur, we outline five epistemic strategies that could be underlying incorporation. Overall, this methodology can be viewed as a diadic and bijective perspective on models that can be applied to other similar cases, using “construction” and “transfer” as complementary handles to probe the available conceptual, structural, and historiographical material.

Advances in Flame Retardant Technologies for Epoxy Resins: Chemical Grafting onto Carbon Fiber Techniques, Reactive Agents, and Applications in Composite Materials.

This review examines recent advancements in flame retardant technologies for epoxy and bio-epoxy resins, focusing on the chemical grafting of hexachlorocyclotriphosphazene (HCCP) onto carbon fibers (CFs) and the use of reactive flame retardant agents in composite materials. It covers various grafting techniques and analyzes mechanisms behind property enhancements, exploring how these approaches improve thermal stability and flame resistance while addressing sustainability challenges. This review discusses the synergistic effects of bio-based materials and innovative grafting methods. It presents applications of flame-retardant epoxy-carbon fiber composites, demonstrating the potential of HCCP-CF composites as high-performance, environmentally friendly structural materials. Additionally, this review evaluates the impact on mechanical properties and interfacial bonding, crucial aspects often affected by flame retardant treatments. This comprehensive overview provides valuable insights, identifying current challenges, future directions, and potential breakthroughs in the field of advanced composite materials.

Synthesis, Purification, and Characterization of Molten Salt Fuel for the SALIENT-03 Irradiation Experiment.

This work presents the synthesis, purification, and characterization of a molten salt fuel for the irradiation experiment SALIENT-03 (SALt Irradiation ExperimeNT), a collaborative effort between the Nuclear Research and Consultancy Group and the Joint Research Centre, European Commission. The primary objective of the project is to investigate the corrosion behavior of selected Ni-alloy based structural materials which are being considered for the construction of fluoride molten salt reactors. During the test, these materials will be exposed to selected liquid molten fuel salts under irradiation in the High Flux Reactor in Petten, the Netherlands. In addition, the properties and distribution of the fission products formed in the fuel salt during burn-up will be studied by various post irradiation examinations. In the SALIENT-03 fuel, U and Pu fluorides, as fissile material, are dissolved in a carrier melt based on a 787LiF-22ThF4 eutectic mixture to form fuel salts with four different compositions, containing PuF3, UF4, UF3, and CrF3. This article comprehensively describes all the steps of this fuel synthesis process: the synthesis of the required pure fluoride powders (7LiF, ThF4, UF4, UF3, and PuF3); the mixing, melting, and purification of the different fuel salt compositions; and the fabrication of solid ingots to be loaded into the irradiation capsules. The characterization of the intermediate and final products is also carried out, following a rigorous quality assurance protocol. The quality assurance is achieved using an analytical scheme consisting of mass balance-based conversion efficiency evaluation, X-ray diffraction, and differential scanning calorimetry analyses. All experimental goals were successfully achieved, highlighting promising prospects for advancing future research and development regarding fuel production methods for fluoride-based molten salt reactors.

Three-dimensional bonding anisotropy of bulk hexagonal metal titanium demonstrated by high harmonic generation

High harmonic generation (HHG) in solid-state materials is an emerging field of photonics research that can unveil the detailed electronic structure of materials, bond strengths and scattering processes of electrons. Although HHG in semiconducting and insulating materials has been intensively investigated both experimentally and theoretically, metals have rarely been explored because the strong screening effect of high-density free electrons is considered to significantly weaken the HHG signal. Here, we investigated HHG upon infrared excitation in bulk hexagonal metal titanium (Ti), a typical building block for practical lightweight structural materials. By analyzing the polarization dependence, the approach revealed the three-dimensional (3D) anisotropy in the electronic states. The results demonstrated the potential of HHG spectroscopy for characterizing 3D bonding anisotropy in metallic systems that are of fundamental importance for designing lightweight and strong structural materials.

High pressure induced superconductivity and chirality-neutral Fermi surface in SrSi2

In this study, we investigate the electronic structure and topological properties of the compound SrSi2 using angle-resolved photoemission spectroscopy (ARPES), electrical transport measurements, and calculations. In contrast to recent theoretical predictions that SrSi2 is a Weyl semimetal with robust Weyl nodes and Fermi arcs, our ARPES measurements on undoped and Ca-doped SrSi2 single crystals show no evidence of the predicted Weyl fermions or Fermi arcs at ambient pressure. Instead, ARPES and transport data show that SrSi2 is a narrow-gap semiconductor at ambient conditions. Our hybrid functional calculations also find a small band gap, in agreement with experiments. However, by applying external pressure, we induce a topological phase transition where the electronic bands overlap and Weyl nodes appear, as confirmed by transport measurements and calculations. Interestingly, we also observe a pressure-induced superconducting transition above 20 GPa. Our results establish SrSi2 as a platform to study the interplay between topological states and superconductivity driven by external pressure. Importantly, our results challenge the previously predicted intrinsic Weyl semimetallic nature of SrSi2 and highlight the need for combined experimental and advanced computational approaches to correctly describe the complex electronic structures in topological materials. Published by the American Physical Society 2024

Mesoporous Carbon Composites Containing Carbon Nanostructures: Recent Advances in Synthesis and Applications in Electrochemistry.

Carbon nanostructures (CNs) are various low-dimensional allotropes of carbon that have attracted much scientific attention due to their interesting physicochemical properties. It was quickly discovered that the properties of CNs can be significantly improved by modifying their surface or synthesizing composites containing CNs. Composites combine two or more materials to create a final material with enhanced properties compared with their initial components. In this review, we focused on one group of carbon materials-composites containing CNs (carbon/CN composites), characterized by high mesoporosity. Particular attention was paid to the type of synthesis used, divided into hard- and soft-templating methods, the type of polymer matrix precursors and their preparation method, heteroatom doping, pore formation methods, and correlations between the applied experimental conditions of synthesis and the structural properties of the composite materials obtained. In the last part, we present an updated summary of the applications of mesoporous composites in energy storage systems, supercapacitors, electrocatalysis, etc. The correlations among porous structures of materials, heteroatom doping, and electrochemical or catalytic efficiency, including activity, selectivity, and stability, were also emphasized. To our knowledge, a single review has never summarized pyrolyzed mesoporous composites of polymer-CNs, their properties and applications in electrochemistry.

Enhancing puncture resistance in critical applications: A combined experimental and numerical approach

The qualification of materials for puncture resistance is essential for applications like pressure vessels and transport containers, particularly for the safe transport of radioactive materials. International regulations, set forth by organizations such as the International Atomic Energy Agency (IAEA) and the Atomic Energy Regulatory Commission (AERB), mandate the design of transport packages capable of withstanding various accident scenarios, including puncture, fire, impact, and immersion, to ensure the safety and integrity of radioactive material transport. This paper establishes a correlation between puncture energy ( E) required to penetrate stainless steel and mild steel plates, both with and without lead backing, as a function of plate thickness ( t) and punch diameter ( d). The simulation of strain and damage caused by punch impact is carried out within the elastoplastic region of structural materials, with a focus on the kinetic strengthening of the material. Abaqus finite element software is employed for numerical simulations, with model parameters derived from experimental stress-strain flow curve data using a curve-fitting technique. Dynamic compression experiments were conducted at the Refueling Technology Division (RTD) in the Bhabha Atomic Research Center (BARC) across a range of strain rates from 600 [Formula: see text] to 1750 [Formula: see text] at room temperature, using a Split Hopkinson Pressure bar. Additionally, drop weight tower (DWT) experiments were performed at RTD in the BARC facility to calibrate numerical simulations. These experiments were carried out on both bare and leaded stainless steel (SS304L) and mild steel (SA516Gr70) plates.

God is a Boltzmann Brane: Arriving at God via Physicalism

ABSTRACT This paper argues that there was, is, or will be, at least one randomly fluctuated, yet, sustaining, godlike Boltzmann Brane/Consciousness, in addition to biological brains that developed slowly via natural processes. Put differently, a godlike being can be arrived at via a strictly physicalist framework, where the key point is that entropy is a statistical, not absolute law. The paper bolsters this core thesis via Roger Penrose's CCC-Theory and Alfred North Whitehead's process panentheism. Lastly, the claim is made that consciousness exists in numerous states of matter, appearing via nucleation around sites of impurities and unusual material structures.

Polycrystalline CoOx-Bo Hybrid as Proficient Electrocatalyst for Addressing Kinetically Sluggish Anodic Reaction in Water Splitting.

Herein, we demonstrated that a polycrystalline cobalt oxide/borate (CoOx-Bo) hybrid catalyst prepared by coprecipitation followed a simple annealing process with a viable boron source of less hazardous ammonium borate, an efficient electrocatalyst for the oxygen evolution reaction (OER). The borate species in the crystalline cobalt oxide lattice provides a tunable polycrystalline morphology with a defect-rich lattice and numerous grain boundaries in the CoOx-Bo hybrid electrocatalyst, which significantly boosts the OER activity compared to the crystalline counterparts of Co3O4 and precious IrO2 in a harsh alkaline electrolyte (1 M KOH). The borate modulated CoOx-Bo achieves a 10 mA/cm2 geometrical current density for the OER with a very low overpotential (η) of 271 mV and small Tafel slope of 34 mV dec-1, in an inert glassy carbon (GC) support, while only requiring η10 of 267 and 32 mV dec-1 in a 3D nickel foam (NF) support at the same current density. The CoOx-Bo catalyst assembled in a two-electrode system with a standard Pt-C cathode only consumed 1.53 V potential bias and exhibited robust stability up to 150 h@10 mA/cm2. The CoOx-Bo is irreversibly oxidized to CoOOH active transformation via surface reconstruction during the OER condition. The cyclic voltammogram (CV) profiles, RRDE evaluation, and postcharacterization observation revealed the formation of a CoOOH active phase upon the long-term OER process and corresponding surface reconstruction. This research provides a new way to synthesize defect-rich, short-range ordered structures of polycrystalline materials with numerous grain boundaries and lays valuable experimental and postcharacterization foundations for the structure and properties of OER catalysts.

Preparing Al2O3/TiO2 nano-multilayers on the surface of FeAl/Al2O3 coating as tritium permeation barrier

Abstract Preparing tritium permeation barrier (TPB) coating on the surface of structural materials can effectively alleviate tritium permeation in fusion reactor system. However, due to the existence of inevitable certain number of defects in TPB, there is still a gap between the commonly prepared TPB coatings and the requirements proposed by fusion reactors. In this work, composite coatings with Al2O3/TiO2 nano-multilayers (NMLs) covering on the surface of FeAl/Al2O3 coating were prepared as TPB. The FeAl/Al2O3 TPB coating on the surface of 316L stainless steel was prepared by electrochemical deposition of Al, aluminization and in-situ oxidation. Due to the aggregation of Cr, there are micro sized defects in the Al2O3 layer. The presence of defects seriously reduces its hydrogen isotopes permeation resistance. The atomic layer deposition was then adopted to prepare Al2O3/TiO2 NMLs with period thickness of 15, 7.5 and 3 nm on the surface of Al2O3 layer, which not only cover the defects, but also utilize interfaces to suppress hydrogen isotopes permeation. The composite coating sample with the period thickness of 3 nm showed great enhancement of two orders of magnitude in deuterium permeation resistance property compared to the original FeAl/Al2O3 TPB coating at 500 °C, and the permeation reduction factor reaches a high value of 5 × 105, which far above the requirements of future fusion reactors.

Numerical Study on the Static Bending Response of Cracked Wind Turbine Blades Reinforced with Graphene Platelets.

With the growing demand for wind energy, the development of advanced materials for wind turbine support structures and blades has garnered significant attention in both industry and academia. In previous research, the authors investigated the incorporation of graphene platelets (GPLs) into wind turbine blades, focusing on the structural performance and cost-effectiveness relative to conventional fiberglass composites. These studies successfully demonstrated the potential advantages of GPL reinforcement in improving blade performance and reducing the blade's weight and costs. Building upon prior work, the present study conducts a detailed investigation into the static bending behavior of GPL-reinforced wind turbine blades, specifically examining the impact of crack location and length. A finite element model of the SNL 61.5 m wind turbine blade was rigorously developed and validated through comparison with the existing literature to ensure its accuracy. Comprehensive parametric analyses were performed to assess deflection under various crack lengths and positions, considering both flapwise and edgewise bending deformations. The findings indicate that GPL-reinforced blades exhibit reduced sensitivity to crack propagation compared to traditional fiberglass blades. Furthermore, the paper presents a thorough parametric analysis of the effects of crack location and length on blade performance.

Advancements in Marine Vessel Design: A Twenty-Four-Year Bibliometric Survey on Technological, Environmental, and Sustainable Progress

Marine vessel design plays a key role in optimizing global trade, environmental sustainability, and technological advancements in naval architecture. However, a comprehensive review of research trends, key advancements, and future directions in sustainable marine vessel design has been lacking. This study addresses this gap by conducting a bibliometric analysis of 1701 publications from the Web of Science Core Collection database from 2000 to 2024. Using CiteSpace and VOSviewer, this research explores global research patterns, key institutions, and the evolution of thematic areas in sustainable marine vessel design over the last 24 years. The results reveal significant contributions from countries such as China, the USA, and South Korea, emphasizing sustainable technologies, safety, structural integrity, and intelligent systems in vessel design. Key research hotspots include “optimization”, “modeling”, “simulation”, and “computational fluid dynamics (CFD)”, reflecting the growing use of advanced technologies to improve vessel efficiency, environmental sustainability, and safety. This study also highlights the importance of interdisciplinary collaboration involving structural engineering, fluid mechanics, materials science, and environmental science. By mapping the historical landscape, current dynamics, and future directions of sustainable marine vessel design, this study aims to provide a foundation for advancing scientific discourse and practical applications in this field.