Search Results (6,812)

Pervious concrete is challenged by the inherent trade-off between permeability and mechanical strength. This study presents a systematic optimization of its mix design to achieve a balance between these properties. Single-factor experiments and an L₉(3³) orthogonal array test were employed to evaluate the effects of target porosity (14–26%), water–cement ratio (0.26–0.34), sand rate (0–10%), and VMA dosage (0–0.02%). Additionally, Spearman rank correlation analysis and nonlinear regression fitting were utilized to develop quantitative relationships correlating the measured porosity to material performance. The results revealed that increasing target porosity enhances permeability but reduces compressive and splitting tensile strengths. The optimal water-to-cement ratio (w/c) was found to be 0.32, balancing both permeability and strength. An appropriate sand content of 6% improved mechanical properties, while a VMA dosage of 0.01% effectively enhanced bonding strength and workability. The orthogonal experiment identified the optimal mix ratio as a w/c ratio of 0.3, VMA dosage of 0.12%, target porosity of 14%, and sand content of 7%, achieving a compressive strength at 28-days of 43.5 MPa and a permeability coefficient of 2.57 mm·s⁻¹. Empirical relationships for the permeability coefficient and mechanical properties as functions of the measured porosity were derived, demonstrating a positive exponential correlation between the measured porosity and the permeability coefficient, and a negative correlation with compressive and splitting tensile strengths. This research provides a systematic framework for designing high-performance pervious concrete with balanced permeability and mechanical properties, offering valuable insights for its development and application in green infrastructure projects. Full article

This present review aims to provide a clear overview of the environmental impact of non-biodegradable materials, and the use of biodegradable materials as their replacements. Non-biodegradable polymers have been used in the past, and now they are considered a threat to the environment. Recently, it has become a necessity to manufacture products with biodegradable polymers to alleviate waste pollution because they can degrade in a short period of time in the environment. Biodegradable polymers can be used in various applications like cosmetics, coatings, wound dressings, gene delivery, and tissue engineering scaffolds. Blending biodegradable polymers could provide an excellent opportunity to produce innovative green biocomposites suitable for any desired applications. This paper reviews all the recent related works on biodegradable PLA and PCL materials and the introduction of fillers for the development of green biocomposites. The properties and characterisation of PLA/PCL blends and PLA-PCL-filler green biocomposites on morphology, thermal, mechanical, thermomechanical, and barrier properties are thoroughly reviewed. The applications, limitations, and future prospects of these green biocomposites is also highlighted. Full article

Oxidative stress is a major contributor to skin aging and related disorders. This study comparatively evaluated the bioefficacy of Schinus terebinthifolius Raddi leaf extracts prepared using three extraction techniques: conventional extraction (CE), accelerated solvent extraction (ASE), and pulsed electric field (PEF) extraction, with 50% (v/v) ethanol and water as green solvents. Among all tested conditions, the CE-derived extract (C-4), obtained with 50% (v/v) ethanol for 120 min, exhibited the highest extraction yield (29.7%). It also showed the highest total phenolic (668.56 ± 11.52 mg gallic acid equivalent (GAE)/g dry material (DM)) and flavonoid content (2629.92 ± 112.61 mg quercetin equivalent (QE)/100 g DM), and potent antioxidant activity against 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical (12,645.50 ± 60.31 µmol Trolox equivalent (TE)/g DM) and oxygen radical absorbance capacity assay (ORAC: 7180.27 ± 101.79 µM TE/100 g DM). Liquid Chromatography coupled with Mass Spectrometry (LC-MS) analysis revealed a diverse phytochemical profile rich in polyphenols, including gallic acid, p-coumaric acid, rutin, rosmarinic acid, caffeic acid, and epicatechin. Cellular assays in hydrogen peroxide (H₂O₂)-induced HaCaT keratinocytes demonstrated that C-4 extract significantly enhanced cell viability and upregulated endogenous antioxidant genes (superoxide dismutase (SOD1), catalase (CAT), glutathione peroxidase (GPX)), with effects comparable to established antioxidants such as epigallocatechin gallate (EGCG) and ascorbic acid. These findings highlight the influence of extraction parameters on phytochemical yield and biological activity, supporting the potential application of CE-derived S. terebinthifolius extracts as effective, sustainable ingredients for cosmeceutical formulations targeting oxidative stress-mediated skin aging. Full article

As the region with the earliest housing stock market and the most advanced development in China, the Pearl River Delta has experienced extensive housing demolition and construction, leading to buildings having short lifespans. The environmental pollution generated during this process has brought attention to the concept of green buildings. However, whether due to previous patterns of demolition and construction or the significant impacts of social and economic changes in the current and future housing stock contexts, the comprehensive adaptability of human-centered living spaces remains a crucial issue. This focus is strongly related to the residents’ psychological responses, such as sense of belonging, safety, and atmosphere, across different scales of physical environment. However, most housing evaluation systems regarding sustainable issues are green building evaluation systems. And their concept and practice are often accompanied by a neglect of the interrelationship between people and the built environment, as well as a lack of an appropriate methodological framework to integrate these elements in the temporal dimension. This paper primarily tries to provide new answers to old questions about housing durability by reconceptualizing evaluation systems beyond ecological metrics, while simultaneously challenging accepted answers that privilege material and energy indicators over sociocultural embeddedness. Moreover, an effective housing evaluation framework must transcend purely technical or ecological indicators to systematically integrate the temporal and sociocultural factors that sustain long-term residential quality, particularly in rapidly transforming urban contexts. Therefore, theories closely related to building longevity, such as open building and the “level” strategy, were introduced. Based on this combined methodological framework, selected cases of local traditional housing and green building evaluation systems were studied, aiming to identify valuable longevity factors and improved evaluation methods. Furthermore, two rounds of expert consultation and a data analysis were conducted. The first round helped determine the local indexes and preliminary evaluation methods, while the second round helped confirm the weighting value of each index through a questionnaire study and data analysis. This systematic study ultimately established a preliminary long-term housing evaluation system for the Pearl River Delta. Full article

This work reports a low-cost, microwave-assisted wet chemistry synthesis of zinc antimonate (ZnSb₂O₆) powders with a trirutile structure, yielding highly homogeneous, nanometric particles. X-ray diffraction (XRD) confirmed the formation of the trirutile phase with lattice parameters of a = 4.664 Å and c = 9.263 Å, and an estimated crystallite size of 42 nm. UV–vis spectroscopy revealed a bandgap of 3.35 eV. Scanning electron microscopy (SEM) showed that ethylenediamine, as a chelating agent, formed porous microstructures of microrods and cuboids, ideal for enhanced gas adsorption. Brunauer–Emmett–Teller (BET) analysis revealed a specific surface area of 6 m²/g and a total pore volume of 0.0831 cm³/g, indicating a predominantly mesoporous structure. The gas sensing properties of ZnSb₂O₆ pellets were evaluated in CO and C₃H₈ atmospheres at 100, 200, and 300 °C. The material exhibited high sensitivity at 300 °C, where the maximum responses were 5.86 for CO at 300 ppm and 1.04 for C₃H₈ at 500 ppm. The enhanced sensitivity at elevated temperatures was corroborated by a corresponding decrease in electrical resistivity. Furthermore, the material demonstrated effective photocatalytic activity, achieving up to 60% degradation of methylene blue and 50% of malachite green after 300 min of UV irradiation, with the process following first-order reaction kinetics. These results highlight that ZnSb₂O₆ synthesized by this method is a promising bifunctional material for gas sensing and photocatalytic applications. Full article

In this study, the impact resistance of WUF-B steel frame beam–column joints under fire was investigated using ABAQUS finite element software through a sequential thermal–mechanical coupling approach. By integrating a room-temperature impact model with a single-sided fire field applied to the lower flange of the steel beam, the multi-parameter influence mechanisms—including temperature (150–750 °C), fire area distribution, and impact momentum—were systematically analyzed. Results indicate that elevated temperatures significantly degrade structural impact resistance. At 750 °C, the peak impact force decreases by 73.3% compared to room temperature, while the mid-span bending moment increases by 63.3%. When the fire zone is near the impact point, localized thermal softening further reduces the peak impact force. Under constant impact energy, lower momentum (i.e., higher velocity) accelerates the rebound of the falling mass, revealing the role of momentum transfer efficiency in governing the transient response of high-temperature structures. Additionally, an analytical prediction model based on Timoshenko beam theory and thermo-mechanical stiffness degradation is developed. By introducing a segmented temperature reduction function, the model significantly enhances the accuracy of mid-span displacement predictions for steel structures under fire. Full article

Prolonged exposure to landfill leachate can weaken the impermeability of liner systems, leading to leachate leakage and the contamination of surrounding soil and water. To improve loess impermeability to enable its use as a liner material, this study uses synthetic landfill leachate to investigate its effects on loess permeability via a series of laboratory tests. This study focused on the influence of varying dosages of calcium lignosulfonate (CLS) on loess permeability, along with its capacity to adsorb and immobilize heavy metal ions. Microscale characterization techniques, including Zeta potential analysis, X-ray fluorescence spectroscopy (XRF), and scanning electron microscopy (SEM), were employed to investigate the impermeability mechanisms of CLS-modified loess and its adsorption behavior toward heavy metals. The results indicate that the permeability coefficient of loess decreases significantly with increasing compaction, while higher leachate concentrations lead to a notable increase in permeability. At a compaction degree of 0.90, the permeability coefficient was reduced to 8 × 10⁻⁸ cm/s. In contrast, under conditions of maximum leachate concentration, the permeability coefficient rose markedly to 1.5 × 10⁻⁴ cm/s. Additionally, increasing the dosage of the compacted loess stabilizer (CLS) effectively reduced the permeability coefficient of the modified loess to 7.1 × 10⁻⁵ cm/s, indicating improved impermeability and enhanced resistance to contaminant migration. With the prolonged infiltration time of landfill leachate, the removal efficiency of Pb²⁺ gradually decreases and stabilizes, while the Pb²⁺ removal efficiency of the modified loess increased by approximately 40%. CLS-modified loess, through multiple mechanisms, reduces the fluid flow pathways and enhances its adsorption capacity for Pb²⁺, thereby improving the soil’s protection against heavy metal contamination. While these results demonstrate the potential of CLS-modified loess as a sustainable landfill liner material, the findings are based on controlled laboratory conditions with Pb²⁺ as the sole target contaminant. Future work should evaluate long-term performance under field conditions, including seasonal wetting–drying and freeze–thaw cycles, and investigate multi-metal systems to validate the broader applicability of this modification technique. Full article

The exponential increase in global solid waste generation poses significant environmental, economic, and social challenges, particularly in rapidly urbanizing regions. Traditional waste management methods that focus on handling and disposal have proven unsustainable because of their negative impacts on air, soil, and water quality, and their contribution to greenhouse gas emissions. In response, the concept of zero-waste cities, rooted in circular economy principles, has gained increasing attention in recent years. This study proposes a comprehensive and integrated waste management system designed to optimize resource recovery across four distinct waste streams: household, healthcare, green/organic, and inert. The system integrates four specialized facilities: a Secondary Sorting Facility, Energy Recovery Facility, Composting Facility, and Inert Processing Facility, coordinated through a central Primary Sorting Hub. By enabling interconnectivity between these processing units, the system facilitates material cascading, maximizes the reuse and recycling of secondary raw materials, and supports energy recovery and circular nutrient flow. The anticipated benefits include enhanced operational efficiency, reduced environmental degradation, and generation of multiple revenue streams. However, the implementation of such a system faces challenges related to high capital investment, technological complexity, regulatory fragmentation, and low public acceptance. Overcoming these limitations will require strategic planning, stakeholder engagement, and adaptive governance. Full article

The circular economy (CE) aims to reduce environmental degradation by ensuring the continuous use of materials and energy resources, aligning with the decarbonization agenda. However, despite the rising acceptance of CE concepts, the economic and managerial aspects remain underexplored in policy and practice. Therefore, this study seeks to bridge the knowledge–practice gap by studying how technology-driven innovation, renewable energy, and energy efficiency interact with CE principles to advance sustainable environmental connections in a detailed manner. The economic analysis of this study was conducted using two base and moderation models, utilizing global data from 78 developing and developed countries, and applying Fixed Effect, Random Effect, and Generalized Method of Moments estimates. The samples were selected based on data availability from internationally recognized databases from 2010 to 2021. The key findings suggest that technology-driven innovation and renewable energy reduce carbon emissions, whereas gross domestic product (GDP) growth and energy efficiency show no standalone positive effects. Notably, moderation effects reveal that the integration of technology with GDP promotes sustainability outcomes, but energy efficiency and renewable energy interact negatively with emissions, a contradictory result warranting further policy investigation. CE-driven innovation promotes decarbonization by striking a balance between environmental preservation, economic expansion, and technology uptake. This study emphasizes region-specific techniques and offers policy insights for combining the CE with natural capital and green GDP. It increases the knowledge of how circular business models powered by technology support sustainable growth and the shift to a circular economy. Full article

This review provides a comprehensive analysis of recent developments in the additive manufacturing of green composites, with a particular focus on their mechanical behavior. A bibliometric analysis of 482 research articles indexed in the Web of Science Core Collection and published between 2015 and 2025 reveals a sharp increase in publications, with dominant contributions from countries such as China, India, and the United States, as well as strong collaboration networks centered on materials science and polymer engineering. Thematic clustering highlights a growing emphasis on natural fiber reinforcement, biodegradable matrices, and performance optimization. Despite these advances, few studies have combined bibliometric analysis with a technical evaluation of mechanical performance, leaving a gap in understanding the relationship between research trends and material or process optimization. Building on these insights, the review synthesizes current knowledge on material composition, print parameters, infill design, and post-processing, identifying their combined effects on tensile strength, stiffness, and durability. The study concludes that multi-variable optimization—encompassing fiber-matrix compatibility, print architecture, and thermal control—is essential to achieving eco-efficient and high-performance green composites in additive manufacturing. Full article

Lubricating oils are utilised in equipment and machinery to reduce friction and enhance material utilisation. The utilisation of oil leads to an increase in its thickness and density over time. Current methods for assessing oil life are slow, expensive, and complex, and often only applicable in laboratory settings and unsuitable for real-time or field use. This leads to unexpected equipment failures, unnecessary oil changes, and economic and environmental losses. A comprehensive review of the extant literature revealed no studies and no national or international patents on neural network algorithm-based oil life modelling and classification using green sensors. In order to address this research gap, this study, for the first time in the literature, provides a green conductivity sensor with high-accuracy prediction of oil life by integrating real-time field measurements and artificial neural networks. This design is based on analysing resistance change using a relatively low-cost, three-dimensional, eco-friendly sensor. The sensor is characterised by its simplicity, speed, precision, instantaneous measurement capability, and user-friendliness. The MLP and LVQ algorithms took as input the resistance values measured in two different oil types (diesel, bench oil) after 5–30 h of use. Depending on their degradation levels, they classified the oils as ‘diesel’ or ‘bench oil’ with 99.77% and 100% accuracy. This study encompasses a sensing system with a sensitivity of 50 µS/cm, demonstrating the proposed methodologies’ efficacy. A next-generation decision support system that will perform oil life determination in real time and with excellent efficiency has been introduced into the literature. The components of the sensor structure under scrutiny in this study are conducive to the creation of zero waste, in addition to being environmentally friendly and biocompatible. The developed three-dimensional green sensor simultaneously detects physical (resistance change) and chemical (oxidation-induced polar group formation) degradation by measuring oil conductivity and resistance changes. Measurements were conducted on simulated contaminated samples in a laboratory environment and on real diesel, gasoline, and industrial oil samples. Thanks to its simplicity, rapid applicability, and low cost, the proposed method enables real-time data collection and decision-making in industrial maintenance processes, contributing to the development of predictive maintenance strategies. It also supports environmental sustainability by preventing unnecessary oil changes and reducing waste. Full article

With the rapid development of the sports industry and the in-depth implementation of the national fitness strategy, sports flooring—as a core component of sports venues—significantly impacts athletic safety and performance. This paper reviews four kinds of popular used sports flooring that are mainly differentiated by their material composition. We summarize the structure, mechanical properties based on international and national standards, environmental adaptability, green sustainability, and smart functionality of the sports flooring. This study compares similarities and differences in international and domestic standardization systems, and analyzes key challenges in multifunctional integration, green sustainability, smart interactivity, and standardized development. Furthermore, future directions in this area, including multi-scale performance modeling, modular smart systems, green material alternatives, and personalized scenario adaptation, are proposed in this study. This work provides theoretical support and technical references for sports facility engineering, smart venue construction, and healthy sports environments. Full article

Heparin-based delivery platforms have gained increasing attention in regenerative medicine due to their exceptional affinity for growth factors and versatility in structural and functional design. This review first introduces the molecular biosynthesis and physicochemical diversity of heparin, which underpin its binding selectivity and degradability. It then categorizes the delivery platforms into microspheres, nanofibers, and hydrogels, with detailed discussions on their fabrication techniques, biofunctional integration of heparin, and release kinetics. Special focus is given to stimuli-responsive systems—including pH-, enzyme-, redox-, thermal-, and ultrasound-sensitive designs—which allow spatiotemporal control over growth factor release. The platform applications are organized by tissue types, encompassing soft tissue regeneration, bone and cartilage repair, neuroregeneration, cardiovascular regeneration, wound healing, anti-fibrotic therapies, and cancer microenvironment modulation. Each section provides recent case studies demonstrating how heparin enhances the bioactivity, localization, and therapeutic efficacy of pro-regenerative or anti-pathologic growth factors. Collectively, these insights highlight heparin’s dual role as both a carrier and modulator, positioning it as a pivotal component in next-generation, precision-targeted delivery systems. Full article

This study presents a plant-fabricated nanoparticle system of zirconia (ZrO₂) using Sonchus asper plant extract, compared with conventionally synthesized ZrO_2, for their efficacy in Cr(VI) removal from aqueous solutions. The nanoparticles were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS) for elemental composition, Fourier-transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analysis. The plant-fabricated ZrO₂ exhibited mesoporosity and enhanced surface functionality, attributed to bioactive compounds from Sonchus asper, which improved adsorption performance via increased surface area and residual organic functional groups. Batch adsorption experiments showed that Cr(VI) removal was optimized at 100 mg/L Cr(VI), 300 mg/L adsorbent dosage, pH 5, and 30 min reaction time at 25 °C. Adsorption followed the Langmuir isotherm and pseudo-second-order kinetics models. According to Langmuir model fitting, the maximum adsorption capacity (qmax) reached 142.24 mg/g for PF-ZrO₂ NPs and 133.11 mg/g for conventional ZrO₂ NPs, indicating the superior adsorption performance of the green-synthesized material. This work highlights the sustainable potential of plant-fabricated ZrO₂ nanoparticles as cost-effective and environmentally friendly nano-adsorbents for heavy metal remediation, contributing to the achievement of UN SDG No. 6 by providing clean water solutions. Full article

Organic phase change materials (OPCMs) offer high energy density for thermal storage but suffer from crystallization kinetics dependent on ambient temperature, leading to uncontrolled heat release and limited storage lifetime. Although doping OPCMs with azobenzene (Azo) derivatives enables optically controlled energy storage and release, existing systems require UV irradiation for E-to-Z isomerization. This UV dependency seriously hinders their development in practical solar applications. Herein, we develop a visible-light-responsive Azo@OPCM composite by doping tetra-ortho-fluorinated azobenzene into eicosane. Systematic characterization of composites with different dopant ratios via UV–visible spectroscopy and differential scanning calorimetry reveals that green-light irradiation drives E-to-Z isomerization, achieving 97–99% Z-isomer conversion. This photoisomerization could introduce supercooling through photo-responsive energy barriers generated by Z-isomer, allowing thermal energy storage at lower temperatures. Subsequent blue-light irradiation triggers Z-to-E reversion to eliminate supercooling and enable optically controlled heat release. Additionally, by regulating the molar ratios of dopant, the optimized composites achieved 280.76 J/g energy density at 20% molar doping ratio, which surpassed that of pure eicosane and the reported Azo-based photothermal energy storage system. This work establishes a complete visible-light-controlled energy harvesting–storage–release cycle with significant potential for near-room-temperature solar thermal storage applications. Full article