In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arre...In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arresting materials are discussed. Theoretical calculations of oxidation of spherical aluminum powders in a typical gas fluidization bed are demonstrated. Computer software written by the author is used to carry out the basic calculations of important parameters of a gas fluidization bed at different temperatures. A mathematical model of the dynamic system in a gas fluidization bed is developed and the analytical solution is obtained. The mathematical model can be used to estimate aluminum oxide thickness at a defined temperature. The mathematical model created in this study is evaluated and confirmed consistently with the experimental results on a gas fluidization bed. Detail technical discussion of the oxidation mechanism of aluminum is carried out. The mathematical deviations of the mathematical modeling have demonstrated in great details. This mathematical model developed in this study and validated with experimental results can bring a great value for the quantitative analysis of a gas fluidization bed in general from a theoretical point of view. It can be applied for the oxidation not only for aluminum spherical powders, but also for other spherical metal powders. The mathematical model developed can further enhance the applications of gas fluidization technology. In addition to the development of mathematical modeling of a gas fluidization bed reactor, the formation of oxide film through diffusion on both planar and spherical aluminum surfaces is analyzed through a thorough mathematical deviation using diffusion theory and Laplace transformation. The dominant defects and their impact to oxidation of aluminum are also discussed in detail. The well-controlled oxidation film on spherical metal powders such as aluminum and other metal spherical powders can potentially become an important part of switch devices of surge arresting materials, in general.展开更多
Smart Materials are along with Innovation attributes and Artificial Intelligence among the most used “buzz” words in all media. Central to their practical occurrence, many talents are to be gathered within new conte...Smart Materials are along with Innovation attributes and Artificial Intelligence among the most used “buzz” words in all media. Central to their practical occurrence, many talents are to be gathered within new contextual data influxes. Has this, in the last 20 years, changed some of the essential fundamental dimensions and the required skills of the actors such as providers, users, insiders, etc.? This is a preliminary focus and prelude of this review. As an example, polysaccharide materials are the most abundant macromolecules present as an integral part of the natural system of our planet. They are renewable, biodegradable, carbon neutral with low environmental, health and safety risks and serve as structural materials in the cell walls of plants. Most of them are used, for many years, as engineering materials in many important industrial processes, such as pulp and papermaking and manufacture of synthetic textile fibres. They are also used in other domains such as conversion into biofuels and, more recently, in the design of processes using polysaccharide nanoparticles. The main properties of polysaccharides (e.g. low density, thermal stability, chemical resistance, high mechanical strength…), together with their biocompatibility, biodegradability, functionality, durability and uniformity, allow their use for manufacturing smart materials such as blends and composites, electroactive polymers and hydrogels which can be obtained 1) through direct utilization and/or 2) after chemical or physical modifications of the polysaccharides. This paper reviews recent works developed on polysaccharides, mainly on cellulose, hemicelluloses, chitin, chitosans, alginates, and their by-products (blends and composites), with the objectives of manufacturing smart materials. It is worth noting that, today, the fundamental understanding of the molecular level interactions that confer smartness to polysaccharides remains poor and one can predict that new experimental and theoretical tools will emerge to develop the necessary understanding of the structure-property-function relationships that will enable polysaccharide-smartness to be better understood and controlled, giving rise to the development of new and innovative applications such as nanotechnology, foods, cosmetics and medicine (e.g. controlled drug release and regenerative medicine) and so, opening up major commercial markets in the context of green chemistry.展开更多
One of the major challenges in designing and fabricating Spintronic devices is the choice of both, Materials and the Technology, along with understanding the intricacies of the Designing aspects. In this communication...One of the major challenges in designing and fabricating Spintronic devices is the choice of both, Materials and the Technology, along with understanding the intricacies of the Designing aspects. In this communication, we have attempted to briefly discuss these factors, with an aim to draw the attention of the Materials Scientists and Technologists to this serious challenge, in the direction of which, though a lot of research and development work has been done, still needs more concerted efforts to be made in order to make the Spintronic devices that can offer good efficiency for maximizing their usefulness.展开更多
Several available mechanistic-empirical pavement design methods fail to include predictive model for permanent deformation(PD)of unbound granular materials(UGMs),which make these methods more conservative.In addition,...Several available mechanistic-empirical pavement design methods fail to include predictive model for permanent deformation(PD)of unbound granular materials(UGMs),which make these methods more conservative.In addition,there are limited regression models capable of predicting the PD under multistress levels,and these models have regression limitations and generally fail to cover the complexity of UGM behaviour.Recent researches are focused on using new methods of computational intelligence systems to address the problems,such as artificial neural network(ANN).In this context,we aim to develop an artificial neural model to predict the PD of UGMs exposed to repeated loads.Extensive repeated load triaxial tests(RLTTs)were conducted on base and subbase materials locally available in Victoria,Australia to investigate the PD properties of the tested materials and to prepare the database of the neural networks.Specimens were prepared over different moisture contents and gradations to cover a wide testing matrix.The ANN model consists of one input layer with five neurons,one hidden layer with twelve neurons,and one output layer with one neuron.The five inputs were the number of load cycles,deviatoric stress,moisture content,coefficient of uniformity,and coefficient of curvature.The sensitivity analysis showed that the most important indicator that impacts PD is the number of load cycles with influence factor of 41%.It shows that the ANN method is rapid and efficient to predict the PD,which could be implemented in the Austroads pavement design method.展开更多
With the start of the new year,Wen Congxiang,managing director of Ningbo Nuoding,a company specialising in the recycling of end-of-life vehicles,has been constantly on the move.Much of his time is spent coordinating w...With the start of the new year,Wen Congxiang,managing director of Ningbo Nuoding,a company specialising in the recycling of end-of-life vehicles,has been constantly on the move.Much of his time is spent coordinating with vehicle collection firms,electric bicycle manufacturers and recycled materials distributors,as he works to build partnerships focused on the targeted collection and distribution of recycled products.展开更多
Conventional electron and optical microscopy techniques require the sample to be sectioned, polished or etched to expose the internal surfaces for imaging. However, such sample preparation techniques have traditionall...Conventional electron and optical microscopy techniques require the sample to be sectioned, polished or etched to expose the internal surfaces for imaging. However, such sample preparation techniques have traditionally prevented the observation of the same sample over time, under realistic three-dimensional geometries and in an environment representative of real-world operating conditions. X-ray microscopy (XRM) is a rapidly emerging technique that enables non-destructive evaluation of buried structures within hard to soft materials in 3D, requiring little to no sample preparation. Furthermore in situ and 4D quantification of microstructural evolution under controlled environment as a function of time, temperature, chemistry or stress can be done repeatable on the same sample, using practical specimen sizes ranging from tens of microns to several cm diameter, with achievable imaging resolution from submicron to 50 nm. Many of these studies were reported using XRM in synchrotron beamlines. These include crack propagation on composite and construction materials; corrosion studies; microstructural changes during the setting of cement; flow studies within porous media to mention but a few.展开更多
Biomedical applications necessitate natural or synthetic biomaterials that can maintain,improve,or even replace damaged tissue or a biological function,facilitating healing for people who have suffered from an injury ...Biomedical applications necessitate natural or synthetic biomaterials that can maintain,improve,or even replace damaged tissue or a biological function,facilitating healing for people who have suffered from an injury or disease.Metallic biomaterials show superior mechanical properties with greater service life than other materials.Biodegradable materials can avoid the inevitable second operation of removing the implant in the case of temporary implantation,reducing the risk of infections,medical complications,healing time,and cost.Magnesium(Mg),zinc(Zn),iron(Fe),and their alloys are potential biodegradable metallic materials.The characteristics of biodegradable metallic materials are variable and depend on many factors,such as alloying elements,microstructure,existing phases,and thermomechanical treatment.The current review emphasizes the impact of alloying element addition on the characteristics of metallic biodegradable materials,with particular attention to the relationships between alloying elements,microstructure,mechanical performance,corrosion,and biocompatibility.Mg alloys show good mechanical and corrosion properties with excellent biocompatibility.Using biocompatible alloying elements can improve Mg alloy mechanical and corrosion properties without af-fecting their biocompatibility.However,critical limitations are still maintained,like rapid degradation and gas bubble formation.Zn alloys could overcome the limitations of Mg alloys with appropriate degradation rates,ease of casting and processing,and good biocompatibility.Alloying,particularly with Mg,Li,and Cu,combined with thermomechanical treatment,can significantly affect the microstructure and mechanical performance of Zn alloys and overcome the problem of unsuitable mechanical properties.Fe alloys have excellent mechanical performance,formability,and biocompatibility with a low degradation rate.Applying surface treatment,using novel structures,alloying with the appropriate amount of alloying elements,and using advanced manufacturing techniques may present a way to solve the problems associated with biodegradable metallic materials,which could open new horizons and increase their applicability in biomedical applications.展开更多
Corn starch(CS)is a renewable,biodegradable polysaccharide valued for its film-forming ability,yet native CS films exhibit lowmechanical strength,highwater sensitivity,and limited thermal stability.This study improves...Corn starch(CS)is a renewable,biodegradable polysaccharide valued for its film-forming ability,yet native CS films exhibit lowmechanical strength,highwater sensitivity,and limited thermal stability.This study improves CS-based films by blending with poly(vinyl alcohol)(PVA)or glycerol(GLY)and using citric acid(CA)as a green,non-toxic cross-linker.Composite films were prepared by casting CS–PVA or CS-GLY with CA at 0%-0.20%(w/w of starch).The influence of CA on physicochemical,mechanical,optical,thermal,and water barrier properties was evaluated.CA crosslinking markedly enhanced the tensile strength,water resistance,and thermal stability of CS-PVA films while increasing transparency in CS–GLY films.At 0.20%CA,the composite achieved 34.99MPa tensile strength,reducedwater vapor permeability,andminimized water uptake.FTIR confirmed ester bond formation between CAand hydroxyl groups of CS,PVA,and GLY,whereas thermal analysis showed higher decomposition temperatures and lower weight loss in crosslinked films.Increasing CA levels also decreased opacity and improved light transmittance,indicating greater homogeneity and reduced crystallinity.This dual-polymer matrix combined with a natural crosslinking strategy provides a sustainable route to high-performance,biodegradable CS-based packaging materials.展开更多
As electronic devices continue to evolve toward higher power densities,faster speeds,and smaller form factors,the demand for high-performance electronic packaging materials has become increasingly critical.These mater...As electronic devices continue to evolve toward higher power densities,faster speeds,and smaller form factors,the demand for high-performance electronic packaging materials has become increasingly critical.These materials serve as the physical and functional interface between semiconductor components and their operating environment,impacting the overall reliability,thermal management,mechanical protection,and electrical performance of modern electronic systems.This study investigates the development,formulation,and performance evaluation of advanced packaging materials,focusing on polymer-based composites,metal and ceramic matrix systems,and nanomaterial-enhanced formulations.A comprehensive analysis of key performance metrics-including thermal conductivity,electrical insulation,mechanical robustness,and environmental resistance-is presented,alongside strategies for material optimization through interface engineering and processing innovations.Furthermore,the study explores cutting-edge integration technologies such as 3D packaging compatibility,low-temperature co-firing,and high-density interconnects.The findings provide critical insights into the structure-property-processing relationships that define the effectiveness of next-generation packaging materials and offer a roadmap for material selection and system integration in high-reliability electronic applications.展开更多
In the context of diminishing energy resources and worsening greenhouse effect,thermoelectric materials have great potential for sustainable development due to their green and environmentally friendly characteristics....In the context of diminishing energy resources and worsening greenhouse effect,thermoelectric materials have great potential for sustainable development due to their green and environmentally friendly characteristics.Among inorganic thermoelectric materials,copper sulfide compounds have greater potential than others due to their abundant element reserves on Earth,lower usage costs,non-toxicity,and good biocompatibility.Compared to organic thermoelectric materials,the"phonon liquid-electron crystal"(PLEC)feature of copper sulfide compounds makes them have stronger thermoelectric performance.This review summarizes the latest research progress in the synthesis methods and thermoelectric modification strategies of copper sulfide compounds.It first explains the importance of the solid-phase method in the manufacture of thermoelectric devices,and then focuses on the great potential of nanoscale synthesis technology based on liquid-phase method in the preparation of thermoelectric materials.Finally,it systematically discusses several strategies for regulating the thermoelectric performance of copper sulfide compounds,including adjusting the chemical proportion of Cu_(2-x)S and introducing element doping to regulate the crystal structure,phase composition,chemical composition,band structure,and nanoscale microstructure of copper sulfide compounds,and directly affecting ZT value by adjusting conductivity and thermal conductivity.In addition,it discusses composite engineering based on copper sulfide compounds,including inorganic,organic,and metal compounds,and discusses tri-component compounds derived from sulfide copper.Finally,it discusses the main challenges and prospects of the development of copper sulfide-based thermoelectric materials,hoping that this review will promote the development of copper sulfide-based thermoelectric materials.展开更多
Magnesium(Mg)and its alloys have been identified as one of the most promising structural,energy and biomaterials owing to their exceptional combination of properties.These include low density,high specific strength,go...Magnesium(Mg)and its alloys have been identified as one of the most promising structural,energy and biomaterials owing to their exceptional combination of properties.These include low density,high specific strength,good damping,high castability,high capacity of hydrogen storage。展开更多
This is a very timely review of body armour materials and systems since new test standards are currently being written, or reviewed, and new, innovative products released. Of greatest importance, however, is the recen...This is a very timely review of body armour materials and systems since new test standards are currently being written, or reviewed, and new, innovative products released. Of greatest importance, however, is the recent evolution, and maturity, of the Ultra High Molecular Weight Polyethylene fibres enabling a completely new style of system to evolve e a stackable system of Hard Armour Plates. The science of body armour materials is quickly reviewed with emphasis upon current understanding of relevant energy-absorbing mechanisms in fibres, fabrics, polymeric laminates and ceramics. The trend in ongoing developments in ballistic fibres is then reviewed, analysed and future projections offered. Weaknesses in some of the ceramic grades are highlighted as is the value of using cladding materials to improve the robustness, and multi-strike performance, of Hard Armour Plates. Finally, with the drive for lighter, and therefore smaller, soft armour systems for military personnel the challenges for armour designers are reported, and the importance of the relative size of the Hard Armour Plate to the Soft Armour Insert is strongly emphasised.展开更多
Repeated load triaxial test is used to assess the deformation behaviour of unbound granular materials(UGMs) in flexible road pavements. Repeated load pulse characteristics(i.e. shape, loading period and rest period) a...Repeated load triaxial test is used to assess the deformation behaviour of unbound granular materials(UGMs) in flexible road pavements. Repeated load pulse characteristics(i.e. shape, loading period and rest period) are the stress configurations used in the experimental set-up to simulate the passing axle loads. Some researchers and standard testing protocols suggest a rest period of varying durations after a loading phase. A thorough review of existing literature and practises has revealed that there is no agreement about the effect of the rest period of vertical stress pulse on the deformation behaviour of the UGMs. Therefore,the main objective of this study is to investigate the effect of repeated stress rest period on the deformation behaviour of UGMs experimentally. Experiments are conducted, both with and without rest period, using basalt and granite crushed rocks from Victoria, Australia. Furthermore, in order to gain insight into the effect of the rest period, finite element modelling is also developed. Both the experimental and modelling results show that the rest period has a noticeable effect on both resilient and permanent deformation behaviours of UGMs. It is, therefore, recommended to take extra precautions while adopting a particular standard testing protocol and to supplement the results by additional tests with different loading configurations.展开更多
Granular materials exhibit complex macroscopic mechanical behaviors closely related to their microscalemicrostructural features.Traditional macroscopic phenomenological elasto-plastic models,however,usually have compl...Granular materials exhibit complex macroscopic mechanical behaviors closely related to their microscalemicrostructural features.Traditional macroscopic phenomenological elasto-plastic models,however,usually have complex formulations and lack explicit relations to these microstructural features.To avoid these limitations,this study proposes a micromechanics-based softening hyperelastic model for granular materials,integrating softening hyperelasticity withmicrostructural insights to capture strain softening,critical state,and strain localization behaviors.The model has two key advantages:(1)a clear conceptualization,straightforward formulation,and ease of numerical implementation(via Abaqus UMAT subroutine in this study);(2)explicit incorporation of micro-scale features(e.g.,contact stiffness,particle size,porosity)to reveal their influences on macroscopic responses.An isotropic directional distribution density of contacts and three specific microstructures are considered,and their softening hyperelastic constitutive modulus tensors are explicitly derived.By introducing a softening factor and critical failure energy density,the model can describe geomaterial behaviors,simulating residual strength,X-shaped shear bands,and strain localization evolution.Numerical validations in comparison with themacro-scale hyperelastic model,Abaqus Drucker-Prager model,and the experiment confirm its accuracy.Parametric studies reveal critical dependencies:a normal to tangential contact stiffness ratio of 2-8(depending on stiffness magnitude),an internal length of 2-4 mm to ensure shear band formation,and a critical failure energy density(≤10 kJ/m^(3))to trigger strain softening and localization.Influences of the specific microstructures on strain localization and softening are investigated.The model also shows mesh independence due to the introduction of an internal length.The model’s applicability is further demonstrated by slope stability analysis,capturing slip surface evolution,and load-displacement characteristics.This study develops a robust microstructure-aware hyperelastic framework to describe the mechanical behaviors of granular materials,providing multiscale insights for geotechnical engineering applications.展开更多
Flash Joule heating(FJH),as a high-efficiency and low-energy consumption technology for advanced materials synthesis,has shown significant potential in the synthesis of graphene and other functional carbon materials.B...Flash Joule heating(FJH),as a high-efficiency and low-energy consumption technology for advanced materials synthesis,has shown significant potential in the synthesis of graphene and other functional carbon materials.Based on the Joule effect,the solid carbon sources can be rapidly heated to ultra-high temperatures(>3000 K)through instantaneous high-energy current pulses during FJH,thus driving the rapid rearrangement and graphitization of carbon atoms.This technology demonstrates numerous advantages,such as solvent-and catalyst-free features,high energy conversion efficiency,and a short process cycle.In this review,we have systematically summarized the technology principle and equipment design for FJH,as well as its raw materials selection and pretreatment strategies.The research progress in the FJH synthesis of flash graphene,carbon nanotubes,graphene fibers,and anode hard carbon,as well as its by-products,is also presented.FJH can precisely optimize the microstructures of carbon materials(e.g.,interlayer spacing of turbostratic graphene,defect concentration,and heteroatom doping)by regulating its operation parameters like flash voltage and flash time,thereby enhancing their performances in various applications,such as composite reinforcement,metal-ion battery electrodes,supercapacitors,and electrocatalysts.However,this technology is still challenged by low process yield,macroscopic material uniformity,and green power supply system construction.More research efforts are also required to promote the transition of FJH from laboratory to industrial-scale applications,thus providing innovative solutions for advanced carbon materials manufacturing and waste management toward carbon neutrality.展开更多
Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes canno...Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes cannot achieve high active material loading and efficient ion/electron transport simultaneously.By contrast,three-dimensional(3D)structures have attracted increasing interest because of their capacity to enhance active material utilization,shorten ion and electron transport pathways,reduce interfacial impedance,and provide spatial accommodation for volume expansion.Additive manufacturing(AM)technology effectively fabricates energy-storage materials with 3D structures by accurately constructing complex 3D structures via layer-by-layer deposition.Recent studies have employed AM to construct ordered 3D electrodes that can optimize ion/electron transport,regulate electric field distribution,or improve the electrode-electrolyte interface,thereby contributing to enhanced kinetic performance and cycling stability.This review systematically summarizes the applications of several AM technologies in the fabrication of energy storage materials and analyzes their respective advantages and limitations.Subsequently,the advantages of AM technology in the fabrication of energy storage materials and several major optimization strategies are comprehensively discussed.Finally,the major challenges and potential applications of AM technology in energy storage material optimization are discussed.展开更多
By leveraging the unique qualities of microorganisms,engineered living materials(ELMs)offer functional and economic advantages in everyday applications along with notable ecological benefits.This study contributes to ...By leveraging the unique qualities of microorganisms,engineered living materials(ELMs)offer functional and economic advantages in everyday applications along with notable ecological benefits.This study contributes to the growing field of biodesign by examining the potential of Flavobacteria for thermochromic ELMs.Many Flavobacteria,commonly found in marine environments,produce iridescent structural colorations as their colonies expand on semi-solid surfaces through gliding motility.In this study,we analyzed the effects of temperature variations on flavobacterium Cellulophaga lytica PLY A 2,characterizing distinct changes in colony growth and iridescent colorations at a macroscopic and microscopic scale.Using scanning electron microscopy,we investigated the relationship between iridescent color and the underlying cell-based optical structures.By providing insights into the temperature-responsive behavior of Flavobacteria,our findings highlight their potential for future thermochromic ELMs-with applications ranging from sustainable food packaging to smart textiles-while encouraging further characterization studies within biodesign research.展开更多
Resorbable bioceramics are attractive for medical applications such as bone substitution. Biochemical analysis on cells cultured on these biomaterials is vital to predict the impact of the materials in vivo and RNA ex...Resorbable bioceramics are attractive for medical applications such as bone substitution. Biochemical analysis on cells cultured on these biomaterials is vital to predict the impact of the materials in vivo and RNA extraction is an essential step in gene expression study using RT-qPCR. In this study, we describe simple modifications to the TRIzol? RNA extraction protocol widely used in biology and these allow high-yield extraction of RNA from cells on resorbable calcium phosphates. Without the modifications, RNA is trapped in the co-precipitated calcium compounds, rendering TRIzol? extraction method infeasible. Among the modifications, the use of extra TRIzol? to dilute the lysate before the RNA precipitation step is critical for extraction of RNA from porous ?-tricalcium phosphate (?-TCP) discs. We also investigate the rationale behind the undesirable precipitation so as to provide clues about the modifications required for other resorbable materials with high application potential in bone tissue engineering.展开更多
Building and construction sector, including infrastructures, are facing many challenges which are scarcity of raw materials, CO2 emissions, lower construction efficiency, and deterioration under corrosive environment ...Building and construction sector, including infrastructures, are facing many challenges which are scarcity of raw materials, CO2 emissions, lower construction efficiency, and deterioration under corrosive environment that cost the world economy $2.5 trillion and this translates to 3.4% of world gross domestic product. This paper presents several examples that show how the use of the nonmetallic materials improved sustainability and life cycles in the built environment by removing the corrosion issue from its root and using durable NM polymers in construction. The paper details recently patented Aramco technology for the use of nonmetallic paving panels that could be used as an alternative to concrete and asphalt paving. Other case studies presented cover use of GFRP Poles for traffic signs and signal poles to replace traditional steel poles. Details of developments for specialist structural application in bridges, in architectural applications, polymers in soils, fibers in pavement manholes and bendable concrete are presented.展开更多
The necessity of having an effective computer-aided decision support system in the housing construction industry is rapidly growing alongside the demand for green buildings and green building products. Identifying and...The necessity of having an effective computer-aided decision support system in the housing construction industry is rapidly growing alongside the demand for green buildings and green building products. Identifying and defining financially viable low-cost green building materials and components, just like selecting them, is a crucial exercise in subjectivity. With so many variables to consider, the task of evaluating such products can be complex and discouraging. Moreover, the existing mode for selecting and managing, often very large information associated with their impacts constrains decision-makers to perform a trade-off analysis that does not necessarily guarantee the most environmentally preferable material. This paper introduces the development of a multi-criteria decision support system (DSS) aimed at improving the understanding of the principles of best practices associated with the impacts of low-cost green building materials and components. The DSS presented in this paper is to provide designers with useful and explicit information that will aid informed decision-making in their choice of materials for low-cost green residential housing projects. The prototype MSDSS is developed using macro-in-excel, which is a fairly recent database management technique used for integrating data from multiple, often very large databases and other information sources. This model consists of a database to store different types of low-cost green materials with their corresponding attributes and performance characteristics. The DSS design is illustrated with particular emphasis on the development of the material selection data schema, and application of the Analytical Hierarchy Process (AHP) concept to a material selection problem. Details of the MSDSS model are also discussed including workflow of the data evaluation process. The prototype model has been developed with inputs elicited from domain experts and extensive literature review, and refined with feedback obtained from selected expert builder and developer companies. This paper further demonstrates the application of the prototype MSDSS for selecting the most appropriate low-cost green building material from among a list of several available options, and finally concludes the study with the associated potential benefits of the model to research and practice.展开更多
文摘In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arresting materials are discussed. Theoretical calculations of oxidation of spherical aluminum powders in a typical gas fluidization bed are demonstrated. Computer software written by the author is used to carry out the basic calculations of important parameters of a gas fluidization bed at different temperatures. A mathematical model of the dynamic system in a gas fluidization bed is developed and the analytical solution is obtained. The mathematical model can be used to estimate aluminum oxide thickness at a defined temperature. The mathematical model created in this study is evaluated and confirmed consistently with the experimental results on a gas fluidization bed. Detail technical discussion of the oxidation mechanism of aluminum is carried out. The mathematical deviations of the mathematical modeling have demonstrated in great details. This mathematical model developed in this study and validated with experimental results can bring a great value for the quantitative analysis of a gas fluidization bed in general from a theoretical point of view. It can be applied for the oxidation not only for aluminum spherical powders, but also for other spherical metal powders. The mathematical model developed can further enhance the applications of gas fluidization technology. In addition to the development of mathematical modeling of a gas fluidization bed reactor, the formation of oxide film through diffusion on both planar and spherical aluminum surfaces is analyzed through a thorough mathematical deviation using diffusion theory and Laplace transformation. The dominant defects and their impact to oxidation of aluminum are also discussed in detail. The well-controlled oxidation film on spherical metal powders such as aluminum and other metal spherical powders can potentially become an important part of switch devices of surge arresting materials, in general.
文摘Smart Materials are along with Innovation attributes and Artificial Intelligence among the most used “buzz” words in all media. Central to their practical occurrence, many talents are to be gathered within new contextual data influxes. Has this, in the last 20 years, changed some of the essential fundamental dimensions and the required skills of the actors such as providers, users, insiders, etc.? This is a preliminary focus and prelude of this review. As an example, polysaccharide materials are the most abundant macromolecules present as an integral part of the natural system of our planet. They are renewable, biodegradable, carbon neutral with low environmental, health and safety risks and serve as structural materials in the cell walls of plants. Most of them are used, for many years, as engineering materials in many important industrial processes, such as pulp and papermaking and manufacture of synthetic textile fibres. They are also used in other domains such as conversion into biofuels and, more recently, in the design of processes using polysaccharide nanoparticles. The main properties of polysaccharides (e.g. low density, thermal stability, chemical resistance, high mechanical strength…), together with their biocompatibility, biodegradability, functionality, durability and uniformity, allow their use for manufacturing smart materials such as blends and composites, electroactive polymers and hydrogels which can be obtained 1) through direct utilization and/or 2) after chemical or physical modifications of the polysaccharides. This paper reviews recent works developed on polysaccharides, mainly on cellulose, hemicelluloses, chitin, chitosans, alginates, and their by-products (blends and composites), with the objectives of manufacturing smart materials. It is worth noting that, today, the fundamental understanding of the molecular level interactions that confer smartness to polysaccharides remains poor and one can predict that new experimental and theoretical tools will emerge to develop the necessary understanding of the structure-property-function relationships that will enable polysaccharide-smartness to be better understood and controlled, giving rise to the development of new and innovative applications such as nanotechnology, foods, cosmetics and medicine (e.g. controlled drug release and regenerative medicine) and so, opening up major commercial markets in the context of green chemistry.
文摘One of the major challenges in designing and fabricating Spintronic devices is the choice of both, Materials and the Technology, along with understanding the intricacies of the Designing aspects. In this communication, we have attempted to briefly discuss these factors, with an aim to draw the attention of the Materials Scientists and Technologists to this serious challenge, in the direction of which, though a lot of research and development work has been done, still needs more concerted efforts to be made in order to make the Spintronic devices that can offer good efficiency for maximizing their usefulness.
文摘Several available mechanistic-empirical pavement design methods fail to include predictive model for permanent deformation(PD)of unbound granular materials(UGMs),which make these methods more conservative.In addition,there are limited regression models capable of predicting the PD under multistress levels,and these models have regression limitations and generally fail to cover the complexity of UGM behaviour.Recent researches are focused on using new methods of computational intelligence systems to address the problems,such as artificial neural network(ANN).In this context,we aim to develop an artificial neural model to predict the PD of UGMs exposed to repeated loads.Extensive repeated load triaxial tests(RLTTs)were conducted on base and subbase materials locally available in Victoria,Australia to investigate the PD properties of the tested materials and to prepare the database of the neural networks.Specimens were prepared over different moisture contents and gradations to cover a wide testing matrix.The ANN model consists of one input layer with five neurons,one hidden layer with twelve neurons,and one output layer with one neuron.The five inputs were the number of load cycles,deviatoric stress,moisture content,coefficient of uniformity,and coefficient of curvature.The sensitivity analysis showed that the most important indicator that impacts PD is the number of load cycles with influence factor of 41%.It shows that the ANN method is rapid and efficient to predict the PD,which could be implemented in the Austroads pavement design method.
文摘With the start of the new year,Wen Congxiang,managing director of Ningbo Nuoding,a company specialising in the recycling of end-of-life vehicles,has been constantly on the move.Much of his time is spent coordinating with vehicle collection firms,electric bicycle manufacturers and recycled materials distributors,as he works to build partnerships focused on the targeted collection and distribution of recycled products.
文摘Conventional electron and optical microscopy techniques require the sample to be sectioned, polished or etched to expose the internal surfaces for imaging. However, such sample preparation techniques have traditionally prevented the observation of the same sample over time, under realistic three-dimensional geometries and in an environment representative of real-world operating conditions. X-ray microscopy (XRM) is a rapidly emerging technique that enables non-destructive evaluation of buried structures within hard to soft materials in 3D, requiring little to no sample preparation. Furthermore in situ and 4D quantification of microstructural evolution under controlled environment as a function of time, temperature, chemistry or stress can be done repeatable on the same sample, using practical specimen sizes ranging from tens of microns to several cm diameter, with achievable imaging resolution from submicron to 50 nm. Many of these studies were reported using XRM in synchrotron beamlines. These include crack propagation on composite and construction materials; corrosion studies; microstructural changes during the setting of cement; flow studies within porous media to mention but a few.
文摘Biomedical applications necessitate natural or synthetic biomaterials that can maintain,improve,or even replace damaged tissue or a biological function,facilitating healing for people who have suffered from an injury or disease.Metallic biomaterials show superior mechanical properties with greater service life than other materials.Biodegradable materials can avoid the inevitable second operation of removing the implant in the case of temporary implantation,reducing the risk of infections,medical complications,healing time,and cost.Magnesium(Mg),zinc(Zn),iron(Fe),and their alloys are potential biodegradable metallic materials.The characteristics of biodegradable metallic materials are variable and depend on many factors,such as alloying elements,microstructure,existing phases,and thermomechanical treatment.The current review emphasizes the impact of alloying element addition on the characteristics of metallic biodegradable materials,with particular attention to the relationships between alloying elements,microstructure,mechanical performance,corrosion,and biocompatibility.Mg alloys show good mechanical and corrosion properties with excellent biocompatibility.Using biocompatible alloying elements can improve Mg alloy mechanical and corrosion properties without af-fecting their biocompatibility.However,critical limitations are still maintained,like rapid degradation and gas bubble formation.Zn alloys could overcome the limitations of Mg alloys with appropriate degradation rates,ease of casting and processing,and good biocompatibility.Alloying,particularly with Mg,Li,and Cu,combined with thermomechanical treatment,can significantly affect the microstructure and mechanical performance of Zn alloys and overcome the problem of unsuitable mechanical properties.Fe alloys have excellent mechanical performance,formability,and biocompatibility with a low degradation rate.Applying surface treatment,using novel structures,alloying with the appropriate amount of alloying elements,and using advanced manufacturing techniques may present a way to solve the problems associated with biodegradable metallic materials,which could open new horizons and increase their applicability in biomedical applications.
基金supported through RIIM Competition funding from the Indonesia Endowment Fund for Education Agency,Ministry of Finance of the Republic of Indonesia and National Research and Innovation Agency of Indonesia according to the contract number:61/IV/KS/5/2023 and 2131/UN6.3.1/PT.00/2023.
文摘Corn starch(CS)is a renewable,biodegradable polysaccharide valued for its film-forming ability,yet native CS films exhibit lowmechanical strength,highwater sensitivity,and limited thermal stability.This study improves CS-based films by blending with poly(vinyl alcohol)(PVA)or glycerol(GLY)and using citric acid(CA)as a green,non-toxic cross-linker.Composite films were prepared by casting CS–PVA or CS-GLY with CA at 0%-0.20%(w/w of starch).The influence of CA on physicochemical,mechanical,optical,thermal,and water barrier properties was evaluated.CA crosslinking markedly enhanced the tensile strength,water resistance,and thermal stability of CS-PVA films while increasing transparency in CS–GLY films.At 0.20%CA,the composite achieved 34.99MPa tensile strength,reducedwater vapor permeability,andminimized water uptake.FTIR confirmed ester bond formation between CAand hydroxyl groups of CS,PVA,and GLY,whereas thermal analysis showed higher decomposition temperatures and lower weight loss in crosslinked films.Increasing CA levels also decreased opacity and improved light transmittance,indicating greater homogeneity and reduced crystallinity.This dual-polymer matrix combined with a natural crosslinking strategy provides a sustainable route to high-performance,biodegradable CS-based packaging materials.
文摘As electronic devices continue to evolve toward higher power densities,faster speeds,and smaller form factors,the demand for high-performance electronic packaging materials has become increasingly critical.These materials serve as the physical and functional interface between semiconductor components and their operating environment,impacting the overall reliability,thermal management,mechanical protection,and electrical performance of modern electronic systems.This study investigates the development,formulation,and performance evaluation of advanced packaging materials,focusing on polymer-based composites,metal and ceramic matrix systems,and nanomaterial-enhanced formulations.A comprehensive analysis of key performance metrics-including thermal conductivity,electrical insulation,mechanical robustness,and environmental resistance-is presented,alongside strategies for material optimization through interface engineering and processing innovations.Furthermore,the study explores cutting-edge integration technologies such as 3D packaging compatibility,low-temperature co-firing,and high-density interconnects.The findings provide critical insights into the structure-property-processing relationships that define the effectiveness of next-generation packaging materials and offer a roadmap for material selection and system integration in high-reliability electronic applications.
文摘In the context of diminishing energy resources and worsening greenhouse effect,thermoelectric materials have great potential for sustainable development due to their green and environmentally friendly characteristics.Among inorganic thermoelectric materials,copper sulfide compounds have greater potential than others due to their abundant element reserves on Earth,lower usage costs,non-toxicity,and good biocompatibility.Compared to organic thermoelectric materials,the"phonon liquid-electron crystal"(PLEC)feature of copper sulfide compounds makes them have stronger thermoelectric performance.This review summarizes the latest research progress in the synthesis methods and thermoelectric modification strategies of copper sulfide compounds.It first explains the importance of the solid-phase method in the manufacture of thermoelectric devices,and then focuses on the great potential of nanoscale synthesis technology based on liquid-phase method in the preparation of thermoelectric materials.Finally,it systematically discusses several strategies for regulating the thermoelectric performance of copper sulfide compounds,including adjusting the chemical proportion of Cu_(2-x)S and introducing element doping to regulate the crystal structure,phase composition,chemical composition,band structure,and nanoscale microstructure of copper sulfide compounds,and directly affecting ZT value by adjusting conductivity and thermal conductivity.In addition,it discusses composite engineering based on copper sulfide compounds,including inorganic,organic,and metal compounds,and discusses tri-component compounds derived from sulfide copper.Finally,it discusses the main challenges and prospects of the development of copper sulfide-based thermoelectric materials,hoping that this review will promote the development of copper sulfide-based thermoelectric materials.
文摘Magnesium(Mg)and its alloys have been identified as one of the most promising structural,energy and biomaterials owing to their exceptional combination of properties.These include low density,high specific strength,good damping,high castability,high capacity of hydrogen storage。
文摘This is a very timely review of body armour materials and systems since new test standards are currently being written, or reviewed, and new, innovative products released. Of greatest importance, however, is the recent evolution, and maturity, of the Ultra High Molecular Weight Polyethylene fibres enabling a completely new style of system to evolve e a stackable system of Hard Armour Plates. The science of body armour materials is quickly reviewed with emphasis upon current understanding of relevant energy-absorbing mechanisms in fibres, fabrics, polymeric laminates and ceramics. The trend in ongoing developments in ballistic fibres is then reviewed, analysed and future projections offered. Weaknesses in some of the ceramic grades are highlighted as is the value of using cladding materials to improve the robustness, and multi-strike performance, of Hard Armour Plates. Finally, with the drive for lighter, and therefore smaller, soft armour systems for military personnel the challenges for armour designers are reported, and the importance of the relative size of the Hard Armour Plate to the Soft Armour Insert is strongly emphasised.
文摘Repeated load triaxial test is used to assess the deformation behaviour of unbound granular materials(UGMs) in flexible road pavements. Repeated load pulse characteristics(i.e. shape, loading period and rest period) are the stress configurations used in the experimental set-up to simulate the passing axle loads. Some researchers and standard testing protocols suggest a rest period of varying durations after a loading phase. A thorough review of existing literature and practises has revealed that there is no agreement about the effect of the rest period of vertical stress pulse on the deformation behaviour of the UGMs. Therefore,the main objective of this study is to investigate the effect of repeated stress rest period on the deformation behaviour of UGMs experimentally. Experiments are conducted, both with and without rest period, using basalt and granite crushed rocks from Victoria, Australia. Furthermore, in order to gain insight into the effect of the rest period, finite element modelling is also developed. Both the experimental and modelling results show that the rest period has a noticeable effect on both resilient and permanent deformation behaviours of UGMs. It is, therefore, recommended to take extra precautions while adopting a particular standard testing protocol and to supplement the results by additional tests with different loading configurations.
基金supported by the National Natural Science Foundation of China through grant numbers 12002245 and 12172263the Science and Technology Research Program of Chongqing Municipal Education Commission through grant number KJQN202300742+1 种基金the National Natural Science Foundation of ChongqingMunicipality through grant number CSTB2025NSCQ-GPX0841Chongqing Jiaotong University through grant number F1220038.
文摘Granular materials exhibit complex macroscopic mechanical behaviors closely related to their microscalemicrostructural features.Traditional macroscopic phenomenological elasto-plastic models,however,usually have complex formulations and lack explicit relations to these microstructural features.To avoid these limitations,this study proposes a micromechanics-based softening hyperelastic model for granular materials,integrating softening hyperelasticity withmicrostructural insights to capture strain softening,critical state,and strain localization behaviors.The model has two key advantages:(1)a clear conceptualization,straightforward formulation,and ease of numerical implementation(via Abaqus UMAT subroutine in this study);(2)explicit incorporation of micro-scale features(e.g.,contact stiffness,particle size,porosity)to reveal their influences on macroscopic responses.An isotropic directional distribution density of contacts and three specific microstructures are considered,and their softening hyperelastic constitutive modulus tensors are explicitly derived.By introducing a softening factor and critical failure energy density,the model can describe geomaterial behaviors,simulating residual strength,X-shaped shear bands,and strain localization evolution.Numerical validations in comparison with themacro-scale hyperelastic model,Abaqus Drucker-Prager model,and the experiment confirm its accuracy.Parametric studies reveal critical dependencies:a normal to tangential contact stiffness ratio of 2-8(depending on stiffness magnitude),an internal length of 2-4 mm to ensure shear band formation,and a critical failure energy density(≤10 kJ/m^(3))to trigger strain softening and localization.Influences of the specific microstructures on strain localization and softening are investigated.The model also shows mesh independence due to the introduction of an internal length.The model’s applicability is further demonstrated by slope stability analysis,capturing slip surface evolution,and load-displacement characteristics.This study develops a robust microstructure-aware hyperelastic framework to describe the mechanical behaviors of granular materials,providing multiscale insights for geotechnical engineering applications.
基金supported by the National Natural Science Foundation of China(52276196)the Foundation of State Key Laboratory of Coal Combustion(FSKLCCA2508)the High-level Talent Foundation of Anhui Agricultural University(rc412307).
文摘Flash Joule heating(FJH),as a high-efficiency and low-energy consumption technology for advanced materials synthesis,has shown significant potential in the synthesis of graphene and other functional carbon materials.Based on the Joule effect,the solid carbon sources can be rapidly heated to ultra-high temperatures(>3000 K)through instantaneous high-energy current pulses during FJH,thus driving the rapid rearrangement and graphitization of carbon atoms.This technology demonstrates numerous advantages,such as solvent-and catalyst-free features,high energy conversion efficiency,and a short process cycle.In this review,we have systematically summarized the technology principle and equipment design for FJH,as well as its raw materials selection and pretreatment strategies.The research progress in the FJH synthesis of flash graphene,carbon nanotubes,graphene fibers,and anode hard carbon,as well as its by-products,is also presented.FJH can precisely optimize the microstructures of carbon materials(e.g.,interlayer spacing of turbostratic graphene,defect concentration,and heteroatom doping)by regulating its operation parameters like flash voltage and flash time,thereby enhancing their performances in various applications,such as composite reinforcement,metal-ion battery electrodes,supercapacitors,and electrocatalysts.However,this technology is still challenged by low process yield,macroscopic material uniformity,and green power supply system construction.More research efforts are also required to promote the transition of FJH from laboratory to industrial-scale applications,thus providing innovative solutions for advanced carbon materials manufacturing and waste management toward carbon neutrality.
基金support of the National Natural Science Foundation of China(No.52574411)Beijing Natural Science Foundation(No.2242043).
文摘Achieving high energy and power densities is currently a core challenge in the fabrication of energy storage materials.Although numerous high-capacity materials have been developed,conventional planar electrodes cannot achieve high active material loading and efficient ion/electron transport simultaneously.By contrast,three-dimensional(3D)structures have attracted increasing interest because of their capacity to enhance active material utilization,shorten ion and electron transport pathways,reduce interfacial impedance,and provide spatial accommodation for volume expansion.Additive manufacturing(AM)technology effectively fabricates energy-storage materials with 3D structures by accurately constructing complex 3D structures via layer-by-layer deposition.Recent studies have employed AM to construct ordered 3D electrodes that can optimize ion/electron transport,regulate electric field distribution,or improve the electrode-electrolyte interface,thereby contributing to enhanced kinetic performance and cycling stability.This review systematically summarizes the applications of several AM technologies in the fabrication of energy storage materials and analyzes their respective advantages and limitations.Subsequently,the advantages of AM technology in the fabrication of energy storage materials and several major optimization strategies are comprehensively discussed.Finally,the major challenges and potential applications of AM technology in energy storage material optimization are discussed.
基金partial support from the Living Circular Labels project,funded by the Taskforce for Applied Research SIA’s KIEM programme(No.CIE.06.007)in the Netherlands。
文摘By leveraging the unique qualities of microorganisms,engineered living materials(ELMs)offer functional and economic advantages in everyday applications along with notable ecological benefits.This study contributes to the growing field of biodesign by examining the potential of Flavobacteria for thermochromic ELMs.Many Flavobacteria,commonly found in marine environments,produce iridescent structural colorations as their colonies expand on semi-solid surfaces through gliding motility.In this study,we analyzed the effects of temperature variations on flavobacterium Cellulophaga lytica PLY A 2,characterizing distinct changes in colony growth and iridescent colorations at a macroscopic and microscopic scale.Using scanning electron microscopy,we investigated the relationship between iridescent color and the underlying cell-based optical structures.By providing insights into the temperature-responsive behavior of Flavobacteria,our findings highlight their potential for future thermochromic ELMs-with applications ranging from sustainable food packaging to smart textiles-while encouraging further characterization studies within biodesign research.
文摘Resorbable bioceramics are attractive for medical applications such as bone substitution. Biochemical analysis on cells cultured on these biomaterials is vital to predict the impact of the materials in vivo and RNA extraction is an essential step in gene expression study using RT-qPCR. In this study, we describe simple modifications to the TRIzol? RNA extraction protocol widely used in biology and these allow high-yield extraction of RNA from cells on resorbable calcium phosphates. Without the modifications, RNA is trapped in the co-precipitated calcium compounds, rendering TRIzol? extraction method infeasible. Among the modifications, the use of extra TRIzol? to dilute the lysate before the RNA precipitation step is critical for extraction of RNA from porous ?-tricalcium phosphate (?-TCP) discs. We also investigate the rationale behind the undesirable precipitation so as to provide clues about the modifications required for other resorbable materials with high application potential in bone tissue engineering.
文摘Building and construction sector, including infrastructures, are facing many challenges which are scarcity of raw materials, CO2 emissions, lower construction efficiency, and deterioration under corrosive environment that cost the world economy $2.5 trillion and this translates to 3.4% of world gross domestic product. This paper presents several examples that show how the use of the nonmetallic materials improved sustainability and life cycles in the built environment by removing the corrosion issue from its root and using durable NM polymers in construction. The paper details recently patented Aramco technology for the use of nonmetallic paving panels that could be used as an alternative to concrete and asphalt paving. Other case studies presented cover use of GFRP Poles for traffic signs and signal poles to replace traditional steel poles. Details of developments for specialist structural application in bridges, in architectural applications, polymers in soils, fibers in pavement manholes and bendable concrete are presented.
文摘The necessity of having an effective computer-aided decision support system in the housing construction industry is rapidly growing alongside the demand for green buildings and green building products. Identifying and defining financially viable low-cost green building materials and components, just like selecting them, is a crucial exercise in subjectivity. With so many variables to consider, the task of evaluating such products can be complex and discouraging. Moreover, the existing mode for selecting and managing, often very large information associated with their impacts constrains decision-makers to perform a trade-off analysis that does not necessarily guarantee the most environmentally preferable material. This paper introduces the development of a multi-criteria decision support system (DSS) aimed at improving the understanding of the principles of best practices associated with the impacts of low-cost green building materials and components. The DSS presented in this paper is to provide designers with useful and explicit information that will aid informed decision-making in their choice of materials for low-cost green residential housing projects. The prototype MSDSS is developed using macro-in-excel, which is a fairly recent database management technique used for integrating data from multiple, often very large databases and other information sources. This model consists of a database to store different types of low-cost green materials with their corresponding attributes and performance characteristics. The DSS design is illustrated with particular emphasis on the development of the material selection data schema, and application of the Analytical Hierarchy Process (AHP) concept to a material selection problem. Details of the MSDSS model are also discussed including workflow of the data evaluation process. The prototype model has been developed with inputs elicited from domain experts and extensive literature review, and refined with feedback obtained from selected expert builder and developer companies. This paper further demonstrates the application of the prototype MSDSS for selecting the most appropriate low-cost green building material from among a list of several available options, and finally concludes the study with the associated potential benefits of the model to research and practice.
