Search Results (18,012)

Compared to glass fiber-reinforced polymer (GFRP) and carbon fiber-reinforced polymer (CFRP), basalt fiber-reinforced polymer (BFRP) offers distinct advantages, including the relatively lower cost and superior creep resistance. As a result, its application in the construction industry has been gaining growing attention. This paper begins by providing an overview of the fundamental background, as well as the mechanical and microscopic properties, of BFs. By exploring various application types, including one-dimensional (e.g., bars, cables), two-dimensional (e.g., grids, sheets), and three-dimensional (e.g., profiles) applications, the research progress of BFRP products in the construction industry is comprehensively summarized. Research has demonstrated the effectiveness of BFRP in a variety of structural applications, such as reinforcing existing structures (e.g., concrete or masonry) using BFRP bars, grids, or sheets, and the development of novel design concepts that integrate BFRP products with existing structural systems. Furthermore, this paper identifies unresolved challenges and proposes potential research directions, intending to promote BFRP’s broader adoption as a standardized and innovative material in the construction industry. Full article

The European Union aims for climate neutrality by 2050 and has proposed the Packaging and Packing Waste Regulation (PPWR) to promote a circular economy, focusing on reducing packaging waste. In this context, a comprehensive sustainability assessment for liquid dairy product packaging, including beverage cartons, bottles and to-go cups, in the DACH region (Germany, Austria and Switzerland) was conducted. The aim was to consider various ecological aspects of environmental impacts and circularity. As the aspect of recyclability is a core aspect in the PPWR, the calculation was of central interest in this project. Here, major differences in the waste management infrastructure between countries could be identified. The majority of assessed packaging falls below the PPWR’s 70% recyclability requirement, with Switzerland showing even lower recyclability due to poor packaging collection and recycling infrastructure. Significant discrepancies in packaging efficiency exist, indicating unnecessary resource consumption, especially in the case of to-go cups. Additionally, the carbon footprint of packaging materials can vary up to ten times within certain product categories, negatively impacting the environment. Good results were identified for the use of certified renewable resources. Overall, the results of the assessment demonstrate several areas for improvement in light of forthcoming regulatory requirements, which must be met in Germany and Austria. Full article

Textile composites are extensively used in structures subjected to both static and dynamic loads. However, research on how loading rates influence performance remains limited. A better understanding of how the rate dependency of matrix materials affects the mechanical behavior of textile composites could facilitate more accurate performance predictions and the efficient selection of components based on loading rates. This study investigates the effect of the rate dependency of epoxy on the overall rate dependency of a plain weave carbon fabric-reinforced epoxy composite. Specimens were prepared using only epoxy resin, and tensile tests were conducted at four loading rates (5 mm/min, 50 mm/min, 200 mm/min, and 800 mm/min) to evaluate changes in the tensile properties of epoxy with varying loading rates. Composite specimens were fabricated using the same epoxy, and tensile tests were performed under identical conditions. The results demonstrated that both materials became more brittle at higher loading rates while their stiffness remained largely unaffected. Furthermore, the failure process of the composite at different loading rates was analyzed through micro-scale finite element analysis. The analysis revealed that the onset of failure in textile composites shifted owing to the rate-dependent brittleness of epoxy. To mitigate the high computational cost of explicit simulations accounting for time dependency, a modified Johnson–Cook model and an acceleration model were newly developed and incorporated into the analysis. Full article

Effective stormwater management is increasingly vital due to climate change impacts, such as intensified rainfall and flooding. Urban expansion, water scarcity, and intensified agriculture demand innovative solutions like Green Stormwater Infrastructure (GSI), including vegetated biofilters, green roofs, wetlands, bioretention systems, and high-rate filtration. These systems, enhanced by natural and engineered filter materials, improve contaminant removal across diverse contexts. Modern practices prioritize retention, infiltration, and groundwater recharge over traditional rapid drainage, reframing stormwater as a resource amid rising extreme weather events. In water-scarce regions, stormwater management offers dual-use potential for drinking and non-drinking applications, addressing freshwater scarcity exacerbated by population growth and climate change. Targeting the “first flush” of pollutants after rainfall allows for more efficient, cost-effective treatment. This paper identifies three key objectives: addressing GSI limitations and exploring new technologies, evaluating treatment train combinations for cost-effective reuse, and advancing urban stormwater treatment research. Various filter media, such as those in green roofs, bioretention systems, and swales, effectively remove pollutants like nutrients, heavy metals, PAHs, and micropollutants. Granular activated carbon (GAC) filters excel at reducing heavy metals and dissolved organic carbon (DOC), with pre-screening via anthracite filters to extend GAC lifespan by trapping sediments and pollutants. Managing emerging contaminants and microplastics remains underexplored and requires further investigation. Full article

The construction field is one of the largest sectors and industries worldwide. This industry is the main industry accused of contributing to greenhouse gases and increasing the effects of climate change. However, the construction industry is indispensable, accordingly in an attempt to decrease the greenhouse gas effects of construction this research presents the manuscript for building a one-story building with all components including waste products. The building model used a strip foundation with a concrete mix design incorporating recycled concrete as a partial replacement for aggregates, cement hollow blocks containing granite waste instead of conventional cement blocks, and sandwiched insulated panels made of wood-plastic composites for the roof. The structural soundness of the system was tested by loading it with a load surpassing its design load in addition to measuring the deflection and checking its abidance to the code limitations. The thermal efficiency was tested by measuring the temperatures in comparison with the outside of the building for a span of 7 days with data recorded every 1 h. Analysis of both the short-term and long-term costs and carbon emissions was performed by acquiring the carbon emissions per unit of material from literature and multiplying it by the quantities of the materials used within the different building alternatives. That study showed that the roofs made of Structural Insulated Panels (SIPs) using Wood-Plastic Composite (WPC) facings when used with hollow-block cement block walls have shown enduring cost efficiency and improved thermal insulation, leading to diminished energy usage, life-cycle expenses, and carbon emissions. Furthermore, the proposed system is more environmentally friendly than conventional reinforced concrete technologies due to their lower costs and emissions in addition to improving sustainability through utilizing recycled materials. Full article

Biosensors harness biological materials as receptors linked to transducers, enabling the capture and transformation of primary biorecognition signals into measurable outputs. This study presents a novel carboxylation method for synthesizing carboxylated graphene (CG) under acidic conditions, enhancing biosensing capabilities. The characterization of the CG was performed using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, thermogravimetric analysis (TGA), and X-ray diffraction (XRD). We modified screen-printed carbon electrodes (SPCEs) with CG to immobilize the SARS-CoV-2 N-protein, facilitating targeted detection of IgA antibodies (IgA-SARS-CoV-2). The analytical performance was assessed via electrochemical techniques such as cyclic voltammetry and electrochemical impedance spectroscopy, confirming CG synthesis effectiveness and biosensor functionality. The developed biosensor efficiently detects IgA-SARS-CoV-2 across a dilution range of 1:1000 to 1:200 v/v in a phosphate-buffered saline (PBS) solution, with a limit of detection calculated at 1:1601 v/v. This device shows considerable potential because of its fast response time, miniaturized design facilitated by SPCEs, reduced sample volume requirements, high sensitivity and specificity, low detection limits, and signal enhancement achieved through nanomaterial integration. Full article

The construction sector plays a key role in the growth of developing countries but faces major environmental challenges, such as greenhouse gas emissions and resource depletion. Life Cycle Assessment (LCA) is an essential tool for evaluating these impacts and promoting sustainable choices. However, its effective application is limited by the lack of local databases. This study introduces a systematic framework (LOCAL-LCID₂) for creating local Life Cycle Inventory (LCI) databases for developing countries. Its application is demonstrated in Burkina Faso’s (BF) context through a comparative LCA of commonly used materials, covering the cradle-to-gate stage. The methodology follows seven steps: (1) identification of materials, (2) data collection, (3) analysis of material and energy flows, (4) development of LCI database, (5) structuring the database using SimaPro 9.6.0, (6) calculation of environmental impacts via ReCiPe 2016 Midpoint, and (7) uncertainty analysis using the pedigree matrix and Monte Carlo simulation. The materials are categorized into two main groups (imported and locally produced) with five subcategories: materials for roofs, walls/structures, floors, openings, and others. The results show that for wall materials, concrete blocks have the highest Global Warming Potential (GWP), with 88.3% of CO₂ emissions attributed to cement, implying an urgent need to optimize cement use and explore alternative binders for sustainable construction. Stabilized earth blocks show intermediate GWP at 65% of concrete block emissions, while straw-stabilized adobe demonstrates the lowest environmental impact, suggesting significant potential for reducing construction’s carbon footprint through traditional material optimization. The importation of steel sheets and ceramic tiles shows high GWP due to their energy-intensive production processes and long-distance transport (4 to 40% of emissions), highlighting opportunities to reduce impacts through local manufacturing and optimization of supply chains. The diversification of BF’s energy mix through clean energy imports from neighboring countries decreases GWP by 26.9%, indicating that regional energy partnerships and renewable energy investments are key pathways for minimizing environmental impacts related to energy consumption in the construction industry. Finally, the uncertainty analysis reveals the need for primary data updates in the current LCI database, highlighting both data quality enhancement opportunities and future research perspectives for industrial process assessment. The methodological framework equips decision-makers in developing countries with tools to implement sustainable construction practices through strategic material selection and regional resource optimization. Full article

This study investigates the dynamics of soil CO₂ emissions during the cover period of Phyllostachys violascens and the impact of different cover measures, aiming to provide references for reducing the environmental effects of bamboo cover. An L₂₇ (9¹³) orthogonal experimental design was employed, setting the following variables: (1) heating materials: chicken manure, straw cake, and wheat ash; (2) thickness of husk layer: 15 cm, 25 cm, and 35 cm; (3) soil moisture levels before covering: moisture to 10 cm, 15 cm, and 20 cm. The soil CO₂ emission rate showed a unimodal curve, with a significant overall increase during the cover period. Throughout the entire cover period, the average soil CO₂ emission rate (25.39 μmol·m⁻²·s⁻¹) was 5.1 times higher than that of the uncovered Lei bamboo forest (5.02 μmol·m⁻²·s⁻¹) during the same period. Thicker husk layers (25 cm and 35 cm) corresponded to higher soil CO₂ emission rates, with significant differences noted among the thicknesses. When the soil was moist to 10 cm, the CO₂ emission rate was highest (62.51 μmol·m⁻²·s⁻¹); moisture to 15 cm and 20 cm resulted in significantly lower emission rates. Chicken manure produced the highest peak CO₂ emissions in the third week, at 70.64 μmol·m⁻²·s⁻¹, while straw cake and wheat ash reached their peaks in the fifth week, at 66.56 μmol·m⁻²·s⁻¹ and 57.58 μmol·m⁻²·s⁻¹, respectively. The interactions between the three factors (heating materials, husk layer thickness, and moisture levels) significantly affected the soil CO₂ emission rates. By optimally configuring these factors, CO₂ emissions can be regulated. This study recommends using wheat ash or straw cake as heating materials, combined with a 25 cm husk layer thickness, and moistening the soil to 15 cm before covering. This approach effectively reduces the peak and total soil CO₂ emissions while ensuring suitable soil temperatures for the growth of bamboo shoots in spring. This research provides a scientific basis for the environmental management of bamboo forests, aiding in the optimization of covering measures to achieve low-carbon and sustainable bamboo management. Full article

Rare earth is an important strategic resource and a key mineral resource for global competition. As the depletion of primary rare-earth resources increases, a great number of rare-earth secondary resources, such as waste phosphor powder collected from fluorescent lamps, cathode-ray tubes, and other luminescent materials, continue to be generated and accumulated. How to achieve the low-carbon extraction and green and efficient utilization of these resources has become an urgent problem to be solved. In recent years, preliminary enrichment methods, such as flotation, magnetic separation, and adsorption, chemical methods, such as acid leaching and alkaline fusion, external-field-enhanced methods (including mechanical activation, microwave and oxidant, green solvent, etc.), and solvent extraction have been used for the separation and extraction of rare-earth elements (REEs), such as Y, Eu, Ce, Tb, La, and Ga, from waste phosphors. In this article, we systematically summarized the research progress of commonly used separation and extraction methods for REEs in waste phosphor powders, analyzed the advantages, disadvantages, and existing problems of different methods, and proposed potential directions for future research. Full article

Lithium metal batteries (LMBs) are promising candidates for electric vehicles (EVs) and next-generation energy storage systems owing to their high energy densities. The solid electrolyte interphase (SEI) on the Li metal anode plays an important role in influencing the Li deposition form and the cycle life of the LMB. However, the SEI on Li metal differs from that for other anodes, such as graphite, owing to its instability and reactivity. In addition, dendrite growth has hindered the commercial application of Li metal batteries in regular portable electronics to EVs. This review summarizes SEI formation on Li metal, dendrite formation and growth, and their impact on battery performance. In addition, we reviewed the recent progress in pretreatment strategies using materials such as polymers, carbon materials, and inorganic compounds to suppress dendritic growth. Full article

Magnesium-based materials, which are known for their light weight and exceptional strength-to-weight ratio, hold immense promise in the biomedical, automotive, aerospace, and military sectors. However, their inherent limitations, including low wear resistance and poor mechanical properties, have driven the development of magnesium-based metal matrix composites (Mg-MMCs). The pivotal role of powder metallurgy (PM) in fabricating Mg-MMCs was explored, enhancing their mechanical and corrosion resistance characteristics. The mechanical characteristics depend upon the fabrication methodology, composition, processing technique, and reinforcement added to the magnesium. PM is identified as the most efficient due to its ability to produce near-net shape composites with high precision, cost-effectiveness, and minimal waste. Furthermore, PM enables precise control over critical processing parameters, such as compaction pressure, sintering temperature, and particle size, which directly influence the composite’s microstructure and properties. This study highlights various reinforcements, mainly carbon nanotubes (CNTs), graphene nanoparticles (GNPs), silicon carbide (SiC), and hydroxyapatite (HAp), and their effects on improving wear, corrosion resistance, and mechanical strength. Among these, CNTs emerge as a standout reinforcement due to their ability to enhance multiple properties when used at optimal weight fractions. Further, this study delves into the interaction between reinforcement types and matrix materials, emphasizing the importance of uniform dispersion in preventing porosity and improving durability. Optimal PM conditions, such as a compaction pressure of 450 MPa, sintering temperatures between 550 and 600 °C, and sintering times of 2 h, are recommended for achieving superior mechanical performance. Emerging trends in reinforcement materials, including nanostructures and bioactive particles, are also discussed, underscoring their potential to widen the application spectrum of Mg-MMCs. Full article

During the exploration of the gravel stratum, incidents such as wellbore leakage, stuck drilling, and unstable wellbore walls frequently occur. These issues lead to diminished drilling efficiency and prolonged construction timelines, ultimately adversely affecting the core recovery rate, resulting in a significant waste of manpower and material resources. To address the issue of hole collapse during drilling, the microbially induced calcite carbonate precipitation (MICP) technique was employed to enhance the properties of bentonite mud drilling fluids. This study analyzed the effects of three factors, i.e., bentonite, biological solution, and barite powder, on the bentonite mud bio-cementation effectiveness through an orthogonal experiment and response surface methodology (RSM). The biological mechanism was examined using scanning electron microscopy (SEM). The experimental results indicated that optimal formulation was achieved when the mass fraction of bentonite was 13.96%, the biological solution comprised 0.6% xanthan gum and 0.4% carboxymethyl cellulose, and the mass fraction of barite was 25%. This research explores the application potential of MICP in enhancing the rheological properties of bentonite mud drilling fluids, which provides new insights and technical references for optimizing their performance. Full article

In this study, micro-scale numerical simulations were performed to evaluate the residual strength of carbon fiber-reinforced polymers (CFRPs) subjected to cyclic transverse and out-of-plane shear loading fatigue. The simulations utilized a finite element method, incorporating an entropy-based damage criterion for the matrix resin. This method aimed to link entropy generation to strength degradation, with the parameter ${\alpha }_o\left(s\right)$ determined as a function of entropy. Cyclic tensile and shear analyses were conducted to correlate residual strength with entropy accumulation, establishing a linear relationship for ${\alpha }_o\left(s\right)$. The results demonstrated meso-scale strength degradation based on micro-scale numerical simulations. Material constants for the epoxy resin matrix were determined through creep and tensile tests, and a generalized Maxwell model with 15 elements was used to represent viscoelastic behavior. Numerical simulations employed the Abaqus/Standard 2020 software, with the epoxy resin matrix behavior implemented via a UMAT subroutine. The analysis revealed a linear relationship between entropy and residual strength for both cyclic tensile and out-of-plane shear loading. This approach enhances experimental insights with numerical predictions, offering a comprehensive understanding of CFRP strength degradation under fatigue loading. This study represents the first numerical approach to link the entropy of the matrix resin at the micro-scale with macro-scale residual strength in CFRP, providing a novel and comprehensive framework for understanding and predicting strength degradation under cyclic loading. Full article

This paper describes a constitutive model for progressive damage in carbon fibre-reinforced composites (CFRPs), developed in the framework of thermodynamics and coupled with a vector equation of state. This made the constitutive model capable of modelling shock wave propagation within orthotropic materials. Damage is incorporated in the model by using reduction in the principal material stiffness based on the effective stress concept and the hypothesis of strain energy equivalence. Damage evolution was defined in terms of a modified Tuler–Bucher criteria. The constitutive model was implemented into Lawrence Livermore National Laboratory (LLNL) DYNA3D nonlinear hydrocode. Simulation results were validated against post-impact experimental data of spherical projectile impact on an aerospace-grade woven CFRP composite panel. Two plate thicknesses were considered and a range of impact velocities above the ballistic limit of the plates, ranging from 194 m/s to 1219 m/s. Other than for the size of the delamination zone in the minor material direction, the discrepancy between the experiments and numerical results for damage and delamination in the CFRP target plates was within 8%. Full article

Introduction: Graphene, a two-dimensional arrangement of carbon atoms, has drawn significant interest in medical research due to its unique properties. In the context of bone regeneration, graphene has shown several promising applications. Its robust structure, electrical conductivity, and biocompatibility make it an ideal candidate for enhancing bone tissue regeneration and repair processes. Studies have revealed that the presence of graphene can stimulate the proliferation and differentiation of bone cells, thereby promoting the formation of new bone tissue. Additionally, its ability to act as an effective carrier for growth factors and drugs allows controlled release, facilitating the engineering of specific tissues for bone regeneration. Aim: To assess the efficacy of graphene in enhancing bone regeneration through in vitro studies, identify key safety concerns, and propose directions for future research to optimize its clinical applicability. Materials and methods: The present systematic review was carried out using the PRISMA 2020 guideline. A first search was carried out on 20 November 2023 and was later updated on 14 February and 15 April 2024 in the databases of PubMed, Scopus, and Web of Science. Those in vitro studies published in English that evaluated the potential for bone regeneration with graphene in dentistry and also those which met the search terms were selected. Furthermore, the quality of the studies was assessed following the modified CONSORT checklist of in vitro studies on dental materials. Results: A total of 17 in vitro studies met the inclusion criteria. Among these, 12 showed increased osteoblast adhesion, proliferation, and differentiation, along with notable enhancements in mineralized matrix formation. Additionally, they exhibited a significant upregulation of osteogenic markers such as RUNX and COL1 (p < 0.05). However, the variability in methodologies and a lack of long-term assessments were noted as critical gaps. Conclusions: The evaluation of the efficacy and safety of graphene in bone regeneration in dentistry revealed significant potential. However, it is recognized that clinical implementation should be approached with caution, considering identified areas of improvement and suggestions for future research. Future studies should focus on standardized experimental designs, including in vivo studies to evaluate long-term safety, immune responses, and vascularization processes in realistic biological environments. Full article